XML 89 R45.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Retirement Benefits (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items] |
Schedule Of SERP Trust Assets, ABO And Contributions |
In Millions
Years Ended December 31 | 2014 | 2013 |
CMS Energy, including Consumers |  |  |  |  |  |  |
Trust assets |  | $ | 131 |  | $ | 136 |
ABO |  |  | 145 |  |  | 122 |
Contributions |  |  | - |  |  | 16 |
Consumers |  |  |  |  |  |  |
Trust assets |  | $ | 93 |  | $ | 96 |
ABO |  |  | 99 |  |  | 82 |
Contributions |  |  | - |  |  | 13 |
Schedule Of Effect Of One-Percentage-Point Change In Assumed Health Care Cost Trend Rates |
In Millions
| One Percentage | One Percentage |
Year Ended December 31, 2014 | Point Increase | Point Decrease |
CMS Energy, including Consumers |  |  |  |  |  |  |
Effect on total service and interest cost component |  | $ | 13 |  | $ | (11) |
Effect on PBO |  |  | 188 |  |  | (165) |
Consumers |  |  |  |  |  |  |
Effect on total service and interest cost component |  | $ | 12 |  | $ | (10) |
Effect on PBO |  |  | 183 |  |  | (161) |
Schedule Of Assumptions Used |
| DB Pension Plan and DB SERP |  | OPEB Plan |
December 31 | 2014 |  | 2013 |  | 2012 |  |  | 2014 |  | 2013 |  | 2012 |  |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Weighted average for benefit obligations |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Discount rate 1 |  | 4.10 | % |  | 4.90 | % |  | 4.10 | % |  |  | 4.30 | % |  | 5.10 | % |  | 4.40 | % |
Mortality table 2 |  | 2014 |  |  | 2000 |  |  | 2000 |  |  |  | 2014 |  |  | 2000 |  |  | 2000 |  |
Rate of compensation increase |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
DB Pension Plan |  | 3.00 | % |  | 3.00 | % |  | 3.00 | % |  |  |  |  |  |  |  |  |  |  |
DB SERP |  | 5.50 | % |  | 5.50 | % |  | 5.50 | % |  |  |  |  |  |  |  |  |  |  |
Weighted average for net periodic benefit cost |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Discount rate 1 |  | 4.90 | % |  | 4.10 | % |  | 4.90 | % |  |  | 5.10 | % |  | 4.40 | % |  | 5.10 | % |
Expected long-term rate of return on plan assets 3 |  | 7.50 | % |  | 7.75 | % |  | 7.75 | % |  |  | 7.25 | % |  | 7.25 | % |  | 7.25 | % |
Mortality table 2 |  | 2000 |  |  | 2000 |  |  | 2000 |  |  |  | 2000 |  |  | 2000 |  |  | 2000 |  |
Rate of compensation increase |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
DB Pension Plan |  | 3.00 | % |  | 3.00 | % |  | 3.50 | % |  |  |  |  |  |  |  |  |  |  |
DB SERP |  | 5.50 | % |  | 5.50 | % |  | 5.50 | % |  |  |  |  |  |  |  |  |  |  |
| 1 |  | The discount rate reflects the rate at which benefits could be effectively settled and is equal to the equivalent single rate resulting from a yield curve analysis. This analysis incorporated the projected benefit payments specific to CMS Energy’s and Consumers’ DB Pension Plan and OPEB Plan and the yields on high quality corporate bonds rated Aa or better.
| 2 |  | The mortality assumption for 2014 for benefit obligations was based on the new RP‑2014 mortality table, with projection scale MP‑2014. The mortality assumption for 2013 and 2012 was based on the RP‑2000 mortality tables with projection of future mortality improvements using Scale AA, which aligned with the IRS prescriptions for cash funding valuations under the Pension Protection Act of 2006. The mortality assumption for all three years for net periodic benefit cost was based on the RP‑2000 mortality table.
| 3 |  | CMS Energy and Consumers determined the long-term rate of return using historical market returns, the present and expected future economic environment, the capital market principles of risk and return, and the expert opinions of individuals and firms with financial market knowledge. CMS Energy and Consumers considered the asset allocation of the portfolio in forecasting the future expected total return of the portfolio. The goal was to determine a long-term rate of return that could be incorporated into the planning of future cash flow requirements in conjunction with the change in the liability. Annually, CMS Energy and Consumers review for reasonableness and appropriateness the forecasted returns for various classes of assets used to construct an expected return model. CMS Energy’s and Consumers’ expected long-term rate of return on DB Pension Plan assets was 7.5 percent in 2014. The actual return on DB Pension Plan assets was 7.4 percent in 2014, 12.5 percent in 2013, and 14.1 percent in 2012.
Schedule Of Net Benefit Costs |
In Millions
| DB Pension Plan and DB SERP |  | OPEB Plan |
Years Ended December 31 | 2014 | 2013 | 2012 |  | 2014 | 2013 | 2012 |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net periodic cost (credit) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Service cost |  | $ | 42 |  | $ | 54 |  | $ | 49 |  |  | $ | 20 |  | $ | 29 |  | $ | 32 |
Interest expense |  |  | 105 |  |  | 100 |  |  | 105 |  |  |  | 56 |  |  | 65 |  |  | 82 |
Expected return on plan assets |  |  | (135) |  |  | (127) |  |  | (125) |  |  |  | (88) |  |  | (77) |  |  | (66) |
Amortization of: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss |  |  | 60 |  |  | 101 |  |  | 79 |  |  |  | 2 |  |  | 26 |  |  | 46 |
Prior service cost (credit) |  |  | 1 |  |  | 3 |  |  | 5 |  |  |  | (41) |  |  | (31) |  |  | (20) |
Net periodic cost (credit) |  | $ | 73 |  | $ | 131 |  | $ | 113 |  |  | $ | (51) |  | $ | 12 |  | $ | 74 |
Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net periodic cost (credit) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Service cost |  | $ | 41 |  | $ | 52 |  | $ | 48 |  |  | $ | 20 |  | $ | 28 |  | $ | 31 |
Interest expense |  |  | 100 |  |  | 96 |  |  | 100 |  |  |  | 54 |  |  | 63 |  |  | 79 |
Expected return on plan assets |  |  | (131) |  |  | (124) |  |  | (122) |  |  |  | (83) |  |  | (72) |  |  | (61) |
Amortization of: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss |  |  | 59 |  |  | 98 |  |  | 77 |  |  |  | 3 |  |  | 27 |  |  | 47 |
Prior service cost (credit) |  |  | 1 |  |  | 3 |  |  | 5 |  |  |  | (40) |  |  | (30) |  |  | (20) |
Net periodic cost (credit) |  | $ | 70 |  | $ | 125 |  | $ | 108 |  |  | $ | (46) |  | $ | 16 |  | $ | 76 |
Schedule Of Net Loss And Prior Service Cost (Credit) That Will Be Amortized In 2015 |
In Millions
| DB Pension Plan | OPEB Plan |
CMS Energy, including Consumers |  |  |  |  |  |  |
Regulatory asset |  | $ | 89 |  | $ | (18) |
AOCI |  |  | 3 |  |  | (2) |
Consumers |  |  |  |  |  |  |
Regulatory asset |  | $ | 89 |  | $ | (18) |
Schedule Of Benefit Obligations In Excess Of Fair Value Of Plan Assets |
In Millions
| DB Pension Plan |  | DB SERP |  | OPEB Plan |
Years Ended December 31 | 2014 | 2013 |  | 2014 | 2013 |  | 2014 | 2013 |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Benefit obligation at beginning of period |  | $ | 2,073 |  | $ | 2,354 |  |  | $ | 132 |  | $ | 144 |  |  | $ | 1,123 |  | $ | 1,729 |
Service cost |  |  | 41 |  |  | 53 |  |  |  | 1 |  |  | 1 |  |  |  | 20 |  |  | 29 |
Interest cost |  |  | 99 |  |  | 94 |  |  |  | 6 |  |  | 6 |  |  |  | 56 |  |  | 65 |
Plan amendments |  |  | - |  |  | - |  |  |  | - |  |  | - |  |  |  | - |  |  | (208) | 2
Actuarial (gain) loss |  |  | 458 |  |  | (308) |  |  |  | 24 |  |  | (12) |  |  |  | 230 |  |  | (440) |
Benefits paid |  |  | (124) |  |  | (120) |  |  |  | (7) |  |  | (7) |  |  |  | (51) | 3 |  | (52) | 3
Benefit obligation at end of period |  | $ | 2,547 |  | $ | 2,073 |  |  | $ | 156 |  | $ | 132 |  |  | $ | 1,378 |  | $ | 1,123 |
Plan assets at fair value at beginning of period |  | $ | 1,964 |  | $ | 1,727 |  |  | $ | - |  | $ | - |  |  | $ | 1,218 |  | $ | 1,047 |
Actual return on plan assets |  |  | 139 |  |  | 206 |  |  |  | - |  |  | - |  |  |  | 72 |  |  | 150 |
Company contribution |  |  | - |  |  | 150 |  |  |  | 7 |  |  | 7 |  |  |  | 25 |  |  | 72 |
Actual benefits paid |  |  | (124) |  |  | (119) |  |  |  | (7) |  |  | (7) |  |  |  | (50) | 3 |  | (51) | 3
Plan assets at fair value at end of period |  | $ | 1,979 |  | $ | 1,964 |  |  | $ | - |  | $ | - |  |  | $ | 1,265 |  | $ | 1,218 |
Funded status |  | $ | (568) | 1 | $ | (109) | 1 |  | $ | (156) |  | $ | (132) |  |  | $ | (113) |  | $ | 95 |
Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Benefit obligation at beginning of period |  |  |  |  |  |  |  |  | $ | 93 |  | $ | 100 |  |  | $ | 1,088 |  | $ | 1,670 |
Service cost |  |  |  |  |  |  |  |  |  | 1 |  |  | 1 |  |  |  | 20 |  |  | 28 |
Interest cost |  |  |  |  |  |  |  |  |  | 4 |  |  | 4 |  |  |  | 54 |  |  | 63 |
Plan amendments |  |  |  |  |  |  |  |  |  | - |  |  | - |  |  |  | - |  |  | (200) | 2
Actuarial (gain) loss |  |  |  |  |  |  |  |  |  | 17 |  |  | (8) |  |  |  | 223 |  |  | (424) |
Benefits paid |  |  |  |  |  |  |  |  |  | (4) |  |  | (4) |  |  |  | (49) | 3 |  | (49) | 3
Benefit obligation at end of period |  |  |  |  |  |  |  |  | $ | 111 |  | $ | 93 |  |  | $ | 1,336 |  | $ | 1,088 |
Plan assets at fair value at beginning of period |  |  |  |  |  |  |  |  | $ | - |  | $ | - |  |  | $ | 1,141 |  | $ | 978 |
Actual return on plan assets |  |  |  |  |  |  |  |  |  | - |  |  | - |  |  |  | 68 |  |  | 141 |
Company contribution |  |  |  |  |  |  |  |  |  | 4 |  |  | 4 |  |  |  | 25 |  |  | 71 |
Actual benefits paid |  |  |  |  |  |  |  |  |  | (4) |  |  | (4) |  |  |  | (48) | 3 |  | (49) | 3
Plan assets at fair value at end of period |  |  |  |  |  |  |  |  | $ | - |  | $ | - |  |  | $ | 1,186 |  | $ | 1,141 |
Funded status |  |  |  |  |  |  |  |  | $ | (111) |  | $ | (93) |  |  | $ | (150) |  | $ | 53 |
| 1 |  | At December 31, 2014, $532 million of the total funded status of the DB Pension Plan was attributable to Consumers, based on an allocation of expenses. At December 31, 2013, $86 million of the total funded status of the DB Pension Plan was attributable to Consumers, based on an allocation of expenses.
| 2 |  | Plan amendments resulted from changing the Medicare drug program provided through the OPEB Plan from an employer-sponsored prescription drug plan with a retiree drug subsidy to an EGWP that began on January 1, 2015, and from certain benefit changes to the OPEB Plan, to begin on January 1, 2016.
| 3 |  | CMS Energy received payments of $4 million in 2014 and $5 million in each of 2013 and 2012 for the Medicare Part D subsidies. Consumers received payments of $4 million in each of 2014 and 2013 and $5 million in 2012 for the Medicare Part D subsidies. The Medicare Part D subsidy payments are used to pay OPEB Plan benefits.
Schedule Of Major Components Of Actuarial Losses |
In Millions
| DB Pension Plan | OPEB Plan |
CMS Energy, including Consumers |  |  |  |  |  |  |
Discount rate change |  | $ | 235 |  | $ | 155 |
RP-2014 mortality table |  |  | 150 |  |  | 145 |
Consumers |  |  |  |  |  |  |
Discount rate change |  |  |  |  | $ | 150 |
RP-2014 mortality table |  |  |  |  |  | 141 |
Schedule Of Retirement Benefit Plan Assets (Liabilities) |
In Millions
December 31 | 2014 | 2013 |
CMS Energy, including Consumers |  |  |  |  |  |  |
Current assets (liabilities) |  |  |  |  |  |  |
DB SERP |  | $ | (8) |  | $ | (8) |
Non-current assets (liabilities) |  |  |  |  |  |  |
DB SERP |  |  | (148) |  |  | (124) |
OPEB Plan |  |  | (113) |  |  | 95 |
DB Pension Plan |  |  | (568) |  |  | (109) |
Consumers |  |  |  |  |  |  |
Current assets (liabilities) |  |  |  |  |  |  |
DB SERP |  | $ | (5) |  | $ | (5) |
Non-current assets (liabilities) |  |  |  |  |  |  |
DB SERP |  |  | (106) |  |  | (88) |
OPEB Plan |  |  | (150) |  |  | 53 |
DB Pension Plan |  |  | (532) |  |  | (86) |
Schedule Of Accumulated And Projected Benefit Obligations |
In Millions
December 31 | 2014 | 2013 |
CMS Energy, including Consumers |  |  |  |  |  |  |
DB Pension Plan PBO |  | $ | 2,547 |  | $ | 2,073 |
DB Pension Plan ABO |  |  | 2,257 |  |  | 1,843 |
Fair value of DB Pension Plan assets |  |  | 1,979 |  |  | 1,964 |
Schedule Of Net Periodic Benefit Cost Not Yet Recognized Including Regulatory Assets |
In Millions
| DB Pension Plan and DB SERP |  | OPEB Plan |
Years Ended December 31 | 2014 | 2013 |  | 2014 | 2013 |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory assets (liabilities) |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss |  | $ | 1,012 |  | $ | 625 |  |  | $ | 419 |  | $ | 184 |
Prior service cost (credit) |  |  | 7 |  |  | 9 |  |  |  | (243) |  |  | (282) |
Regulatory assets (liabilities) |  | $ | 1,019 |  | $ | 634 |  |  | $ | 176 |  | $ | (98) |
AOCI |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss (gain) |  |  | 99 |  |  | 69 |  |  |  | (18) |  |  | (26) |
Prior service cost (credit) |  |  | 1 |  |  | - |  |  |  | (8) |  |  | (10) |
Total amounts recognized in regulatory assets (liabilities) and AOCI |  | $ | 1,119 |  | $ | 703 |  |  | $ | 150 |  | $ | (134) |
Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory assets (liabilities) |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss |  | $ | 1,012 |  | $ | 625 |  |  | $ | 419 |  | $ | 184 |
Prior service cost (credit) |  |  | 7 |  |  | 9 |  |  |  | (243) |  |  | (282) |
Regulatory assets (liabilities) |  | $ | 1,019 |  | $ | 634 |  |  | $ | 176 |  | $ | (98) |
AOCI |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss (gain) |  |  | 39 |  |  | 25 |  |  |  | - |  |  | - |
Total amounts recognized in regulatory assets (liabilities) and AOCI |  | $ | 1,058 |  | $ | 659 |  |  | $ | 176 |  | $ | (98) |
Schedule Of Allocation Of Plan Assets |
In Millions
| DB Pension Plan |
| December 31, 2014 |  | December 31, 2013 |
| Total | Level 1 | Level 2 |  | Total | Level 1 | Level 2 |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset category |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash and short-term investments |  | $ | 31 |  | $ | 31 |  | $ | - |  |  | $ | 109 |  | $ | 109 |  | $ | - |
U.S. government and agencies securities |  |  | 30 |  |  | - |  |  | 30 |  |  |  | 25 |  |  | - |  |  | 25 |
Corporate debt |  |  | 222 |  |  | - |  |  | 222 |  |  |  | 188 |  |  | - |  |  | 188 |
State and municipal bonds |  |  | 8 |  |  | - |  |  | 8 |  |  |  | 5 |  |  | - |  |  | 5 |
Foreign corporate bonds |  |  | 21 |  |  | - |  |  | 21 |  |  |  | 20 |  |  | - |  |  | 20 |
Mutual funds |  |  | 598 |  |  | 598 |  |  | - |  |  |  | 449 |  |  | 449 |  |  | - |
Pooled funds |  |  | 1,069 |  |  | - |  |  | 1,069 |  |  |  | 1,168 |  |  | - |  |  | 1,168 |
Total |  | $ | 1,979 |  | $ | 629 |  | $ | 1,350 |  |  | $ | 1,964 |  | $ | 558 |  | $ | 1,406 |
In Millions
| OPEB Plan |
| December 31, 2014 |  | December 31, 2013 |
| Total | Level 1 | Level 2 |  | Total | Level 1 | Level 2 |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset category |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash and short-term investments |  | $ | 19 |  | $ | 19 |  | $ | - |  |  | $ | 44 |  | $ | 44 |  | $ | - |
U.S. government and agencies securities |  |  | 5 |  |  | - |  |  | 5 |  |  |  | 3 |  |  | - |  |  | 3 |
Corporate debt |  |  | 33 |  |  | - |  |  | 33 |  |  |  | 26 |  |  | - |  |  | 26 |
State and municipal bonds |  |  | 1 |  |  | - |  |  | 1 |  |  |  | 1 |  |  | - |  |  | 1 |
Foreign corporate bonds |  |  | 3 |  |  | - |  |  | 3 |  |  |  | 3 |  |  | - |  |  | 3 |
Common stocks |  |  | 69 |  |  | 69 |  |  | - |  |  |  | 71 |  |  | 71 |  |  | - |
Mutual funds |  |  | 438 |  |  | 438 |  |  | - |  |  |  | 343 |  |  | 343 |  |  | - |
Pooled funds |  |  | 697 |  |  | - |  |  | 697 |  |  |  | 727 |  |  | - |  |  | 727 |
Total |  | $ | 1,265 |  | $ | 526 |  | $ | 739 |  |  | $ | 1,218 |  | $ | 458 |  | $ | 760 |
Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset category |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash and short-term investments |  | $ | 18 |  | $ | 18 |  | $ | - |  |  | $ | 41 |  | $ | 41 |  | $ | - |
U.S. government and agencies securities |  |  | 4 |  |  | - |  |  | 4 |  |  |  | 3 |  |  | - |  |  | 3 |
Corporate debt |  |  | 31 |  |  | - |  |  | 31 |  |  |  | 25 |  |  | - |  |  | 25 |
State and municipal bonds |  |  | 1 |  |  | - |  |  | 1 |  |  |  | 1 |  |  | - |  |  | 1 |
Foreign corporate bonds |  |  | 3 |  |  | - |  |  | 3 |  |  |  | 3 |  |  | - |  |  | 3 |
Common stocks |  |  | 65 |  |  | 65 |  |  | - |  |  |  | 66 |  |  | 66 |  |  | - |
Mutual funds |  |  | 411 |  |  | 411 |  |  | - |  |  |  | 321 |  |  | 321 |  |  | - |
Pooled funds |  |  | 653 |  |  | - |  |  | 653 |  |  |  | 681 |  |  | - |  |  | 681 |
Total |  | $ | 1,186 |  | $ | 494 |  | $ | 692 |  |  | $ | 1,141 |  | $ | 428 |  | $ | 713 |
Schedule Of Investment Components Of Pooled Funds |
| DB Pension Plan |  | OPEB Plan |
December 31 | 2014 |  | 2013 |  |  | 2014 |  | 2013 |  |
U.S. equity securities |  | 64 | % |  | 61 | % |  |  | 62 | % |  | 60 | % |
Foreign equity securities |  | 16 |  |  | 28 |  |  |  | 12 |  |  | 20 |  |
U.S. fixed-income securities |  | 9 |  |  | 4 |  |  |  | 18 |  |  | 14 |  |
Foreign fixed-income securities |  | 6 |  |  | 3 |  |  |  | 5 |  |  | 4 |  |
Alternative investments |  | 5 |  |  | 4 |  |  |  | 3 |  |  | 2 |  |
|  | 100 | % |  | 100 | % |  |  | 100 | % |  | 100 | % |
Schedule Of Plan Contributions |
In Millions
Years Ended December 31 | 2014 | 2013 |
CMS Energy, including Consumers |  |  |  |  |  |  |
OPEB Plan 1 |  |  |  |  |  |  |
VEBA trust |  | $ | 16 |  | $ | 55 |
401(h) component |  |  | 9 |  |  | 17 |
|  | $ | 25 |  | $ | 72 |
DB Pension Plan 2 |  | $ | - |  | $ | 150 |
Consumers |  |  |  |  |  |  |
OPEB Plan 1 |  |  |  |  |  |  |
VEBA trust |  | $ | 16 |  | $ | 55 |
401(h) component |  |  | 9 |  |  | 16 |
|  | $ | 25 |  | $ | 71 |
DB Pension Plan 2 |  | $ | - |  | $ | 147 |
| 1 |  | CMS Energy, including Consumers, plans to contribute $29 million to the OPEB Plan in 2015, of which Consumers plans to contribute $29 million.
| 2 |  | Neither CMS Energy nor Consumers plans to contribute to the DB Pension Plan in 2015.
Schedule Of Expected Benefit Payments |
In Millions
| DB Pension Plan | DB SERP | OPEB Plan |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |
2015 |  | $ | 134 |  | $ | 8 |  | $ | 56 |
2016 |  |  | 141 |  |  | 8 |  |  | 58 |
2017 |  |  | 147 |  |  | 8 |  |  | 61 |
2018 |  |  | 152 |  |  | 8 |  |  | 64 |
2019 |  |  | 156 |  |  | 9 |  |  | 67 |
2020-2024 |  |  | 810 |  |  | 50 |  |  | 367 |
Consumers |  |  |  |  |  |  |  |  |  |
2015 |  | $ | 131 |  | $ | 5 |  | $ | 53 |
2016 |  |  | 137 |  |  | 5 |  |  | 56 |
2017 |  |  | 143 |  |  | 5 |  |  | 59 |
2018 |  |  | 148 |  |  | 5 |  |  | 62 |
2019 |  |  | 152 |  |  | 5 |  |  | 64 |
2020-2024 |  |  | 789 |  |  | 30 |  |  | 352 |
Consumers Energy Company [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Schedule Of SERP Trust Assets, ABO And Contributions |
In Millions
Years Ended December 31 | 2014 | 2013 |
CMS Energy, including Consumers |  |  |  |  |  |  |
Trust assets |  | $ | 131 |  | $ | 136 |
ABO |  |  | 145 |  |  | 122 |
Contributions |  |  | - |  |  | 16 |
Consumers |  |  |  |  |  |  |
Trust assets |  | $ | 93 |  | $ | 96 |
ABO |  |  | 99 |  |  | 82 |
Contributions |  |  | - |  |  | 13 |
Schedule Of Effect Of One-Percentage-Point Change In Assumed Health Care Cost Trend Rates |
In Millions
| One Percentage | One Percentage |
Year Ended December 31, 2014 | Point Increase | Point Decrease |
CMS Energy, including Consumers |  |  |  |  |  |  |
Effect on total service and interest cost component |  | $ | 13 |  | $ | (11) |
Effect on PBO |  |  | 188 |  |  | (165) |
Consumers |  |  |  |  |  |  |
Effect on total service and interest cost component |  | $ | 12 |  | $ | (10) |
Effect on PBO |  |  | 183 |  |  | (161) |
Schedule Of Assumptions Used |
| DB Pension Plan and DB SERP |  | OPEB Plan |
December 31 | 2014 |  | 2013 |  | 2012 |  |  | 2014 |  | 2013 |  | 2012 |  |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Weighted average for benefit obligations |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Discount rate 1 |  | 4.10 | % |  | 4.90 | % |  | 4.10 | % |  |  | 4.30 | % |  | 5.10 | % |  | 4.40 | % |
Mortality table 2 |  | 2014 |  |  | 2000 |  |  | 2000 |  |  |  | 2014 |  |  | 2000 |  |  | 2000 |  |
Rate of compensation increase |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
DB Pension Plan |  | 3.00 | % |  | 3.00 | % |  | 3.00 | % |  |  |  |  |  |  |  |  |  |  |
DB SERP |  | 5.50 | % |  | 5.50 | % |  | 5.50 | % |  |  |  |  |  |  |  |  |  |  |
Weighted average for net periodic benefit cost |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Discount rate 1 |  | 4.90 | % |  | 4.10 | % |  | 4.90 | % |  |  | 5.10 | % |  | 4.40 | % |  | 5.10 | % |
Expected long-term rate of return on plan assets 3 |  | 7.50 | % |  | 7.75 | % |  | 7.75 | % |  |  | 7.25 | % |  | 7.25 | % |  | 7.25 | % |
Mortality table 2 |  | 2000 |  |  | 2000 |  |  | 2000 |  |  |  | 2000 |  |  | 2000 |  |  | 2000 |  |
Rate of compensation increase |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
DB Pension Plan |  | 3.00 | % |  | 3.00 | % |  | 3.50 | % |  |  |  |  |  |  |  |  |  |  |
DB SERP |  | 5.50 | % |  | 5.50 | % |  | 5.50 | % |  |  |  |  |  |  |  |  |  |  |
| 1 |  | The discount rate reflects the rate at which benefits could be effectively settled and is equal to the equivalent single rate resulting from a yield curve analysis. This analysis incorporated the projected benefit payments specific to CMS Energy’s and Consumers’ DB Pension Plan and OPEB Plan and the yields on high quality corporate bonds rated Aa or better.
| 2 |  | The mortality assumption for 2014 for benefit obligations was based on the new RP‑2014 mortality table, with projection scale MP‑2014. The mortality assumption for 2013 and 2012 was based on the RP‑2000 mortality tables with projection of future mortality improvements using Scale AA, which aligned with the IRS prescriptions for cash funding valuations under the Pension Protection Act of 2006. The mortality assumption for all three years for net periodic benefit cost was based on the RP‑2000 mortality table.
| 3 |  | CMS Energy and Consumers determined the long-term rate of return using historical market returns, the present and expected future economic environment, the capital market principles of risk and return, and the expert opinions of individuals and firms with financial market knowledge. CMS Energy and Consumers considered the asset allocation of the portfolio in forecasting the future expected total return of the portfolio. The goal was to determine a long-term rate of return that could be incorporated into the planning of future cash flow requirements in conjunction with the change in the liability. Annually, CMS Energy and Consumers review for reasonableness and appropriateness the forecasted returns for various classes of assets used to construct an expected return model. CMS Energy’s and Consumers’ expected long-term rate of return on DB Pension Plan assets was 7.5 percent in 2014. The actual return on DB Pension Plan assets was 7.4 percent in 2014, 12.5 percent in 2013, and 14.1 percent in 2012.
Schedule Of Net Benefit Costs |
In Millions
| DB Pension Plan and DB SERP |  | OPEB Plan |
Years Ended December 31 | 2014 | 2013 | 2012 |  | 2014 | 2013 | 2012 |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net periodic cost (credit) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Service cost |  | $ | 42 |  | $ | 54 |  | $ | 49 |  |  | $ | 20 |  | $ | 29 |  | $ | 32 |
Interest expense |  |  | 105 |  |  | 100 |  |  | 105 |  |  |  | 56 |  |  | 65 |  |  | 82 |
Expected return on plan assets |  |  | (135) |  |  | (127) |  |  | (125) |  |  |  | (88) |  |  | (77) |  |  | (66) |
Amortization of: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss |  |  | 60 |  |  | 101 |  |  | 79 |  |  |  | 2 |  |  | 26 |  |  | 46 |
Prior service cost (credit) |  |  | 1 |  |  | 3 |  |  | 5 |  |  |  | (41) |  |  | (31) |  |  | (20) |
Net periodic cost (credit) |  | $ | 73 |  | $ | 131 |  | $ | 113 |  |  | $ | (51) |  | $ | 12 |  | $ | 74 |
Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net periodic cost (credit) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Service cost |  | $ | 41 |  | $ | 52 |  | $ | 48 |  |  | $ | 20 |  | $ | 28 |  | $ | 31 |
Interest expense |  |  | 100 |  |  | 96 |  |  | 100 |  |  |  | 54 |  |  | 63 |  |  | 79 |
Expected return on plan assets |  |  | (131) |  |  | (124) |  |  | (122) |  |  |  | (83) |  |  | (72) |  |  | (61) |
Amortization of: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss |  |  | 59 |  |  | 98 |  |  | 77 |  |  |  | 3 |  |  | 27 |  |  | 47 |
Prior service cost (credit) |  |  | 1 |  |  | 3 |  |  | 5 |  |  |  | (40) |  |  | (30) |  |  | (20) |
Net periodic cost (credit) |  | $ | 70 |  | $ | 125 |  | $ | 108 |  |  | $ | (46) |  | $ | 16 |  | $ | 76 |
Schedule Of Net Loss And Prior Service Cost (Credit) That Will Be Amortized In 2015 |
In Millions
| DB Pension Plan | OPEB Plan |
CMS Energy, including Consumers |  |  |  |  |  |  |
Regulatory asset |  | $ | 89 |  | $ | (18) |
AOCI |  |  | 3 |  |  | (2) |
Consumers |  |  |  |  |  |  |
Regulatory asset |  | $ | 89 |  | $ | (18) |
Schedule Of Benefit Obligations In Excess Of Fair Value Of Plan Assets |
In Millions
| DB Pension Plan |  | DB SERP |  | OPEB Plan |
Years Ended December 31 | 2014 | 2013 |  | 2014 | 2013 |  | 2014 | 2013 |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Benefit obligation at beginning of period |  | $ | 2,073 |  | $ | 2,354 |  |  | $ | 132 |  | $ | 144 |  |  | $ | 1,123 |  | $ | 1,729 |
Service cost |  |  | 41 |  |  | 53 |  |  |  | 1 |  |  | 1 |  |  |  | 20 |  |  | 29 |
Interest cost |  |  | 99 |  |  | 94 |  |  |  | 6 |  |  | 6 |  |  |  | 56 |  |  | 65 |
Plan amendments |  |  | - |  |  | - |  |  |  | - |  |  | - |  |  |  | - |  |  | (208) | 2
Actuarial (gain) loss |  |  | 458 |  |  | (308) |  |  |  | 24 |  |  | (12) |  |  |  | 230 |  |  | (440) |
Benefits paid |  |  | (124) |  |  | (120) |  |  |  | (7) |  |  | (7) |  |  |  | (51) | 3 |  | (52) | 3
Benefit obligation at end of period |  | $ | 2,547 |  | $ | 2,073 |  |  | $ | 156 |  | $ | 132 |  |  | $ | 1,378 |  | $ | 1,123 |
Plan assets at fair value at beginning of period |  | $ | 1,964 |  | $ | 1,727 |  |  | $ | - |  | $ | - |  |  | $ | 1,218 |  | $ | 1,047 |
Actual return on plan assets |  |  | 139 |  |  | 206 |  |  |  | - |  |  | - |  |  |  | 72 |  |  | 150 |
Company contribution |  |  | - |  |  | 150 |  |  |  | 7 |  |  | 7 |  |  |  | 25 |  |  | 72 |
Actual benefits paid |  |  | (124) |  |  | (119) |  |  |  | (7) |  |  | (7) |  |  |  | (50) | 3 |  | (51) | 3
Plan assets at fair value at end of period |  | $ | 1,979 |  | $ | 1,964 |  |  | $ | - |  | $ | - |  |  | $ | 1,265 |  | $ | 1,218 |
Funded status |  | $ | (568) | 1 | $ | (109) | 1 |  | $ | (156) |  | $ | (132) |  |  | $ | (113) |  | $ | 95 |
Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Benefit obligation at beginning of period |  |  |  |  |  |  |  |  | $ | 93 |  | $ | 100 |  |  | $ | 1,088 |  | $ | 1,670 |
Service cost |  |  |  |  |  |  |  |  |  | 1 |  |  | 1 |  |  |  | 20 |  |  | 28 |
Interest cost |  |  |  |  |  |  |  |  |  | 4 |  |  | 4 |  |  |  | 54 |  |  | 63 |
Plan amendments |  |  |  |  |  |  |  |  |  | - |  |  | - |  |  |  | - |  |  | (200) | 2
Actuarial (gain) loss |  |  |  |  |  |  |  |  |  | 17 |  |  | (8) |  |  |  | 223 |  |  | (424) |
Benefits paid |  |  |  |  |  |  |  |  |  | (4) |  |  | (4) |  |  |  | (49) | 3 |  | (49) | 3
Benefit obligation at end of period |  |  |  |  |  |  |  |  | $ | 111 |  | $ | 93 |  |  | $ | 1,336 |  | $ | 1,088 |
Plan assets at fair value at beginning of period |  |  |  |  |  |  |  |  | $ | - |  | $ | - |  |  | $ | 1,141 |  | $ | 978 |
Actual return on plan assets |  |  |  |  |  |  |  |  |  | - |  |  | - |  |  |  | 68 |  |  | 141 |
Company contribution |  |  |  |  |  |  |  |  |  | 4 |  |  | 4 |  |  |  | 25 |  |  | 71 |
Actual benefits paid |  |  |  |  |  |  |  |  |  | (4) |  |  | (4) |  |  |  | (48) | 3 |  | (49) | 3
Plan assets at fair value at end of period |  |  |  |  |  |  |  |  | $ | - |  | $ | - |  |  | $ | 1,186 |  | $ | 1,141 |
Funded status |  |  |  |  |  |  |  |  | $ | (111) |  | $ | (93) |  |  | $ | (150) |  | $ | 53 |
| 1 |  | At December 31, 2014, $532 million of the total funded status of the DB Pension Plan was attributable to Consumers, based on an allocation of expenses. At December 31, 2013, $86 million of the total funded status of the DB Pension Plan was attributable to Consumers, based on an allocation of expenses.
| 2 |  | Plan amendments resulted from changing the Medicare drug program provided through the OPEB Plan from an employer-sponsored prescription drug plan with a retiree drug subsidy to an EGWP that began on January 1, 2015, and from certain benefit changes to the OPEB Plan, to begin on January 1, 2016.
| 3 |  | CMS Energy received payments of $4 million in 2014 and $5 million in each of 2013 and 2012 for the Medicare Part D subsidies. Consumers received payments of $4 million in each of 2014 and 2013 and $5 million in 2012 for the Medicare Part D subsidies. The Medicare Part D subsidy payments are used to pay OPEB Plan benefits.
Schedule Of Major Components Of Actuarial Losses |
In Millions
| DB Pension Plan | OPEB Plan |
CMS Energy, including Consumers |  |  |  |  |  |  |
Discount rate change |  | $ | 235 |  | $ | 155 |
RP-2014 mortality table |  |  | 150 |  |  | 145 |
Consumers |  |  |  |  |  |  |
Discount rate change |  |  |  |  | $ | 150 |
RP-2014 mortality table |  |  |  |  |  | 141 |
Schedule Of Retirement Benefit Plan Assets (Liabilities) |
In Millions
December 31 | 2014 | 2013 |
CMS Energy, including Consumers |  |  |  |  |  |  |
Current assets (liabilities) |  |  |  |  |  |  |
DB SERP |  | $ | (8) |  | $ | (8) |
Non-current assets (liabilities) |  |  |  |  |  |  |
DB SERP |  |  | (148) |  |  | (124) |
OPEB Plan |  |  | (113) |  |  | 95 |
DB Pension Plan |  |  | (568) |  |  | (109) |
Consumers |  |  |  |  |  |  |
Current assets (liabilities) |  |  |  |  |  |  |
DB SERP |  | $ | (5) |  | $ | (5) |
Non-current assets (liabilities) |  |  |  |  |  |  |
DB SERP |  |  | (106) |  |  | (88) |
OPEB Plan |  |  | (150) |  |  | 53 |
DB Pension Plan |  |  | (532) |  |  | (86) |
Schedule Of Net Periodic Benefit Cost Not Yet Recognized Including Regulatory Assets |
In Millions
| DB Pension Plan and DB SERP |  | OPEB Plan |
Years Ended December 31 | 2014 | 2013 |  | 2014 | 2013 |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory assets (liabilities) |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss |  | $ | 1,012 |  | $ | 625 |  |  | $ | 419 |  | $ | 184 |
Prior service cost (credit) |  |  | 7 |  |  | 9 |  |  |  | (243) |  |  | (282) |
Regulatory assets (liabilities) |  | $ | 1,019 |  | $ | 634 |  |  | $ | 176 |  | $ | (98) |
AOCI |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss (gain) |  |  | 99 |  |  | 69 |  |  |  | (18) |  |  | (26) |
Prior service cost (credit) |  |  | 1 |  |  | - |  |  |  | (8) |  |  | (10) |
Total amounts recognized in regulatory assets (liabilities) and AOCI |  | $ | 1,119 |  | $ | 703 |  |  | $ | 150 |  | $ | (134) |
Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory assets (liabilities) |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss |  | $ | 1,012 |  | $ | 625 |  |  | $ | 419 |  | $ | 184 |
Prior service cost (credit) |  |  | 7 |  |  | 9 |  |  |  | (243) |  |  | (282) |
Regulatory assets (liabilities) |  | $ | 1,019 |  | $ | 634 |  |  | $ | 176 |  | $ | (98) |
AOCI |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss (gain) |  |  | 39 |  |  | 25 |  |  |  | - |  |  | - |
Total amounts recognized in regulatory assets (liabilities) and AOCI |  | $ | 1,058 |  | $ | 659 |  |  | $ | 176 |  | $ | (98) |
Schedule Of Allocation Of Plan Assets |
In Millions
| DB Pension Plan |
| December 31, 2014 |  | December 31, 2013 |
| Total | Level 1 | Level 2 |  | Total | Level 1 | Level 2 |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset category |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash and short-term investments |  | $ | 31 |  | $ | 31 |  | $ | - |  |  | $ | 109 |  | $ | 109 |  | $ | - |
U.S. government and agencies securities |  |  | 30 |  |  | - |  |  | 30 |  |  |  | 25 |  |  | - |  |  | 25 |
Corporate debt |  |  | 222 |  |  | - |  |  | 222 |  |  |  | 188 |  |  | - |  |  | 188 |
State and municipal bonds |  |  | 8 |  |  | - |  |  | 8 |  |  |  | 5 |  |  | - |  |  | 5 |
Foreign corporate bonds |  |  | 21 |  |  | - |  |  | 21 |  |  |  | 20 |  |  | - |  |  | 20 |
Mutual funds |  |  | 598 |  |  | 598 |  |  | - |  |  |  | 449 |  |  | 449 |  |  | - |
Pooled funds |  |  | 1,069 |  |  | - |  |  | 1,069 |  |  |  | 1,168 |  |  | - |  |  | 1,168 |
Total |  | $ | 1,979 |  | $ | 629 |  | $ | 1,350 |  |  | $ | 1,964 |  | $ | 558 |  | $ | 1,406 |
In Millions
| OPEB Plan |
| December 31, 2014 |  | December 31, 2013 |
| Total | Level 1 | Level 2 |  | Total | Level 1 | Level 2 |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset category |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash and short-term investments |  | $ | 19 |  | $ | 19 |  | $ | - |  |  | $ | 44 |  | $ | 44 |  | $ | - |
U.S. government and agencies securities |  |  | 5 |  |  | - |  |  | 5 |  |  |  | 3 |  |  | - |  |  | 3 |
Corporate debt |  |  | 33 |  |  | - |  |  | 33 |  |  |  | 26 |  |  | - |  |  | 26 |
State and municipal bonds |  |  | 1 |  |  | - |  |  | 1 |  |  |  | 1 |  |  | - |  |  | 1 |
Foreign corporate bonds |  |  | 3 |  |  | - |  |  | 3 |  |  |  | 3 |  |  | - |  |  | 3 |
Common stocks |  |  | 69 |  |  | 69 |  |  | - |  |  |  | 71 |  |  | 71 |  |  | - |
Mutual funds |  |  | 438 |  |  | 438 |  |  | - |  |  |  | 343 |  |  | 343 |  |  | - |
Pooled funds |  |  | 697 |  |  | - |  |  | 697 |  |  |  | 727 |  |  | - |  |  | 727 |
Total |  | $ | 1,265 |  | $ | 526 |  | $ | 739 |  |  | $ | 1,218 |  | $ | 458 |  | $ | 760 |
Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset category |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash and short-term investments |  | $ | 18 |  | $ | 18 |  | $ | - |  |  | $ | 41 |  | $ | 41 |  | $ | - |
U.S. government and agencies securities |  |  | 4 |  |  | - |  |  | 4 |  |  |  | 3 |  |  | - |  |  | 3 |
Corporate debt |  |  | 31 |  |  | - |  |  | 31 |  |  |  | 25 |  |  | - |  |  | 25 |
State and municipal bonds |  |  | 1 |  |  | - |  |  | 1 |  |  |  | 1 |  |  | - |  |  | 1 |
Foreign corporate bonds |  |  | 3 |  |  | - |  |  | 3 |  |  |  | 3 |  |  | - |  |  | 3 |
Common stocks |  |  | 65 |  |  | 65 |  |  | - |  |  |  | 66 |  |  | 66 |  |  | - |
Mutual funds |  |  | 411 |  |  | 411 |  |  | - |  |  |  | 321 |  |  | 321 |  |  | - |
Pooled funds |  |  | 653 |  |  | - |  |  | 653 |  |  |  | 681 |  |  | - |  |  | 681 |
Total |  | $ | 1,186 |  | $ | 494 |  | $ | 692 |  |  | $ | 1,141 |  | $ | 428 |  | $ | 713 |
Schedule Of Investment Components Of Pooled Funds |
| DB Pension Plan |  | OPEB Plan |
December 31 | 2014 |  | 2013 |  |  | 2014 |  | 2013 |  |
U.S. equity securities |  | 64 | % |  | 61 | % |  |  | 62 | % |  | 60 | % |
Foreign equity securities |  | 16 |  |  | 28 |  |  |  | 12 |  |  | 20 |  |
U.S. fixed-income securities |  | 9 |  |  | 4 |  |  |  | 18 |  |  | 14 |  |
Foreign fixed-income securities |  | 6 |  |  | 3 |  |  |  | 5 |  |  | 4 |  |
Alternative investments |  | 5 |  |  | 4 |  |  |  | 3 |  |  | 2 |  |
|  | 100 | % |  | 100 | % |  |  | 100 | % |  | 100 | % |
Schedule Of Plan Contributions |
In Millions
Years Ended December 31 | 2014 | 2013 |
CMS Energy, including Consumers |  |  |  |  |  |  |
OPEB Plan 1 |  |  |  |  |  |  |
VEBA trust |  | $ | 16 |  | $ | 55 |
401(h) component |  |  | 9 |  |  | 17 |
|  | $ | 25 |  | $ | 72 |
DB Pension Plan 2 |  | $ | - |  | $ | 150 |
Consumers |  |  |  |  |  |  |
OPEB Plan 1 |  |  |  |  |  |  |
VEBA trust |  | $ | 16 |  | $ | 55 |
401(h) component |  |  | 9 |  |  | 16 |
|  | $ | 25 |  | $ | 71 |
DB Pension Plan 2 |  | $ | - |  | $ | 147 |
| 1 |  | CMS Energy, including Consumers, plans to contribute $29 million to the OPEB Plan in 2015, of which Consumers plans to contribute $29 million.
| 2 |  | Neither CMS Energy nor Consumers plans to contribute to the DB Pension Plan in 2015.
Schedule Of Expected Benefit Payments |
In Millions
| DB Pension Plan | DB SERP | OPEB Plan |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |
2015 |  | $ | 134 |  | $ | 8 |  | $ | 56 |
2016 |  |  | 141 |  |  | 8 |  |  | 58 |
2017 |  |  | 147 |  |  | 8 |  |  | 61 |
2018 |  |  | 152 |  |  | 8 |  |  | 64 |
2019 |  |  | 156 |  |  | 9 |  |  | 67 |
2020-2024 |  |  | 810 |  |  | 50 |  |  | 367 |
Consumers |  |  |  |  |  |  |  |  |  |
2015 |  | $ | 131 |  | $ | 5 |  | $ | 53 |
2016 |  |  | 137 |  |  | 5 |  |  | 56 |
2017 |  |  | 143 |  |  | 5 |  |  | 59 |
2018 |  |  | 148 |  |  | 5 |  |  | 62 |
2019 |  |  | 152 |  |  | 5 |  |  | 64 |
2020-2024 |  |  | 789 |  |  | 30 |  |  | 352 |

X
- Definition Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) And Regulatory Assets to be Recognized over Next Fiscal Year [Table Text Block] + References No definition available. + Details
Name: | cms_ScheduleOfAmountsInAccumulatedOtherComprehensiveIncomeLossAndRegulatoryAssetsToBeRecognizedOverNextFiscalYearTableTextBlock
Namespace Prefix: | cms_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule Of Investment Components Of Pooled Funds [Table Text Block] + References No definition available. + Details
Name: | cms_ScheduleOfInvestmentComponentsOfPooledFundsTableTextBlock
Namespace Prefix: | cms_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule Of Major Components Of Actuarial Gains (Losses) [Table Text Block] + References No definition available. + Details
Name: | cms_ScheduleOfMajorComponentsOfActuarialGainsLossesTableTextBlock
Namespace Prefix: | cms_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the amounts related to pension plans and/or other employee benefit plans in accumulated other comprehensive income or loss and regulatory assets that have not yet been recognized as components of net periodic benefit cost, such as the net gain (loss), net prior service cost or credit, and net transition asset or obligation. + References No definition available. + Details
Name: | cms_ScheduleOfNetPeriodicBenefitCostNotYetRecognizedIncludingRegulatoryAssetsTableTextBlock
Namespace Prefix: | cms_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of plan contributions made. + References No definition available. + Details
Name: | cms_ScheduleOfPlanContributionsTableTextBlock
Namespace Prefix: | cms_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the DB SERP trust assets market value, amounts contributed to the DB SERP trust, and the ABO of the DB SERP. + References No definition available. + Details
Name: | cms_ScheduleOfSerpTrustAssetsAboAndContributionsTableTextBlock
Namespace Prefix: | cms_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of benefit obligations including accumulated benefit obligation and projected benefit obligation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
Name: | us-gaap_ScheduleOfAccumulatedAndProjectedBenefitObligationsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the major categories of plan assets of pension plans and/or other employee benefit plans. This information may include, but is not limited to, the target allocation of plan assets, the fair value of each major category of plan assets, and the level within the fair value hierarchy in which the fair value measurements fall. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
Name: | us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the amounts that are recognized in the balance sheet (or statement of financial position) for pension plans and/or other employee benefit plans, showing separately the assets and current and noncurrent liabilities (if applicable) recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
Name: | us-gaap_ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the assumptions used to determine for pension plans and/or other employee benefit plans the benefit obligation and net benefit cost, including assumed discount rates, rate increase in compensation increase, and expected long-term rates of return on plan assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
Name: | us-gaap_ScheduleOfAssumptionsUsedTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the aggregate benefit obligation and aggregate fair value of plan assets for pension plans and/or other employee benefit plans with benefit obligations in excess of plan assets as of the measurement date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2417-114920 + Details
Name: | us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the effect of a one-percentage-point increase and the effect of a one-percentage-point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs and the accumulated postretirement benefit obligation for health care benefits. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (m) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
Name: | us-gaap_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of benefits expected to be paid by pension plans and/or other employee benefit plans in each of the next five fiscal years and in the aggregate for the five fiscal years thereafter. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
Name: | us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
Name: | us-gaap_ScheduleOfNetBenefitCostsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=cms_ConsumersEnergyCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |