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Retirement Benefits | 6 Months Ended
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Jun. 30, 2016
Retirement Benefits | 8:Retirement Benefits CMS Energy and Consumers provide pension, OPEB, and other retirement benefits to employees under a number of different plans. In January 2016, CMS Energy and Consumers changed the method they use to determine the discount rate used to calculate the service cost and interest expense components of net periodic benefit costs for the DB Pension and OPEB Plans. Historically, the discount rate used for this purpose represented a single weighted-average rate derived from the yield curve used to determine the benefit obligation. CMS Energy and Consumers have elected to use instead a full-yield-curve approach in the estimation of service cost and interest expense; this approach is more accurate in that it applies individual spot rates along the yield curve to future projected benefit payments based on the time of payment. As a result of changing to the full-yield-curve approach to determine the discount rate, f or the six months ended June 30, 2016, t he service cost and interest expense components of net periodic benefit costs were reduced by $12 millio n for the DB Pension Plan and $6 million for the OPEB Plan for CMS Energy and by $11 million for the DB Pension Plan and $6 million for the OPEB Plan for Consumers. Presented in the following table are the costs (credits) and other changes in plan assets and benefit obligations incurred in CMS Energy’s and Consumers’ retirement benefits plans:
﻿ |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
﻿ |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
﻿In Millions
﻿ | DB Pension Plan |  | OPEB Plan |
﻿ | Three Months Ended |  | Six Months Ended |  | Three Months Ended |  | Six Months Ended |
﻿June 30 | 2016 | 2015 |  | 2016 | 2015 |  | 2016 | 2015 |  | 2016 | 2015 |
﻿CMS Energy, including Consumers
﻿Net periodic cost (credit)
﻿Service cost |  | $ | 10 |  | $ | 12 |  |  | $ | 21 |  | $ | 24 |  |  | $ | 4 |  | $ | 6 |  |  | $ | 9 |  | $ | 12 |
﻿Interest expense |  |  | 22 |  |  | 26 |  |  |  | 43 |  |  | 51 |  |  |  | 11 |  |  | 14 |  |  |  | 23 |  |  | 29 |
﻿Expected return on plan assets |  |  | (37) |  |  | (35) |  |  |  | (74) |  |  | (69) |  |  |  | (21) |  |  | (22) |  |  |  | (43) |  |  | (45) |
﻿Amortization of: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
﻿Net loss |  |  | 18 |  |  | 22 |  |  |  | 35 |  |  | 45 |  |  |  | 6 |  |  | 6 |  |  |  | 11 |  |  | 11 |
﻿Prior service cost (credit) |  |  | 1 |  |  | 1 |  |  |  | 2 |  |  | 1 |  |  |  | (11) |  |  | (11) |  |  |  | (21) |  |  | (21) |
﻿Net periodic cost (credit) |  | $ | 14 |  | $ | 26 |  |  | $ | 27 |  | $ | 52 |  |  | $ | (11) |  | $ | (7) |  |  | $ | (21) |  | $ | (14) |
﻿Consumers
﻿Net periodic cost (credit)
﻿Service cost |  | $ | 10 |  | $ | 12 |  |  | $ | 20 |  | $ | 24 |  |  | $ | 5 |  | $ | 6 |  |  | $ | 9 |  | $ | 12 |
﻿Interest expense |  |  | 21 |  |  | 24 |  |  |  | 42 |  |  | 49 |  |  |  | 11 |  |  | 14 |  |  |  | 22 |  |  | 28 |
﻿Expected return on plan assets |  |  | (36) |  |  | (34) |  |  |  | (72) |  |  | (67) |  |  |  | (20) |  |  | (21) |  |  |  | (40) |  |  | (43) |
﻿Amortization of: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
﻿Net loss |  |  | 17 |  |  | 22 |  |  |  | 34 |  |  | 44 |  |  |  | 5 |  |  | 5 |  |  |  | 11 |  |  | 11 |
﻿Prior service cost (credit) |  |  | 1 |  |  | 1 |  |  |  | 2 |  |  | 1 |  |  |  | (10) |  |  | (10) |  |  |  | (20) |  |  | (20) |
﻿Net periodic cost (credit) |  | $ | 13 |  | $ | 25 |  |  | $ | 26 |  | $ | 51 |  |  | $ | (9) |  | $ | (6) |  |  | $ | (18) |  | $ | (12) |
﻿
Consumers Energy Company [Member] |
Retirement Benefits | 8:Retirement Benefits CMS Energy and Consumers provide pension, OPEB, and other retirement benefits to employees under a number of different plans. In January 2016, CMS Energy and Consumers changed the method they use to determine the discount rate used to calculate the service cost and interest expense components of net periodic benefit costs for the DB Pension and OPEB Plans. Historically, the discount rate used for this purpose represented a single weighted-average rate derived from the yield curve used to determine the benefit obligation. CMS Energy and Consumers have elected to use instead a full-yield-curve approach in the estimation of service cost and interest expense; this approach is more accurate in that it applies individual spot rates along the yield curve to future projected benefit payments based on the time of payment. As a result of changing to the full-yield-curve approach to determine the discount rate, f or the six months ended June 30, 2016, t he service cost and interest expense components of net periodic benefit costs were reduced by $12 millio n for the DB Pension Plan and $6 million for the OPEB Plan for CMS Energy and by $11 million for the DB Pension Plan and $6 million for the OPEB Plan for Consumers. Presented in the following table are the costs (credits) and other changes in plan assets and benefit obligations incurred in CMS Energy’s and Consumers’ retirement benefits plans:
﻿ |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
﻿ |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
﻿In Millions
﻿ | DB Pension Plan |  | OPEB Plan |
﻿ | Three Months Ended |  | Six Months Ended |  | Three Months Ended |  | Six Months Ended |
﻿June 30 | 2016 | 2015 |  | 2016 | 2015 |  | 2016 | 2015 |  | 2016 | 2015 |
﻿CMS Energy, including Consumers
﻿Net periodic cost (credit)
﻿Service cost |  | $ | 10 |  | $ | 12 |  |  | $ | 21 |  | $ | 24 |  |  | $ | 4 |  | $ | 6 |  |  | $ | 9 |  | $ | 12 |
﻿Interest expense |  |  | 22 |  |  | 26 |  |  |  | 43 |  |  | 51 |  |  |  | 11 |  |  | 14 |  |  |  | 23 |  |  | 29 |
﻿Expected return on plan assets |  |  | (37) |  |  | (35) |  |  |  | (74) |  |  | (69) |  |  |  | (21) |  |  | (22) |  |  |  | (43) |  |  | (45) |
﻿Amortization of: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
﻿Net loss |  |  | 18 |  |  | 22 |  |  |  | 35 |  |  | 45 |  |  |  | 6 |  |  | 6 |  |  |  | 11 |  |  | 11 |
﻿Prior service cost (credit) |  |  | 1 |  |  | 1 |  |  |  | 2 |  |  | 1 |  |  |  | (11) |  |  | (11) |  |  |  | (21) |  |  | (21) |
﻿Net periodic cost (credit) |  | $ | 14 |  | $ | 26 |  |  | $ | 27 |  | $ | 52 |  |  | $ | (11) |  | $ | (7) |  |  | $ | (21) |  | $ | (14) |
﻿Consumers
﻿Net periodic cost (credit)
﻿Service cost |  | $ | 10 |  | $ | 12 |  |  | $ | 20 |  | $ | 24 |  |  | $ | 5 |  | $ | 6 |  |  | $ | 9 |  | $ | 12 |
﻿Interest expense |  |  | 21 |  |  | 24 |  |  |  | 42 |  |  | 49 |  |  |  | 11 |  |  | 14 |  |  |  | 22 |  |  | 28 |
﻿Expected return on plan assets |  |  | (36) |  |  | (34) |  |  |  | (72) |  |  | (67) |  |  |  | (20) |  |  | (21) |  |  |  | (40) |  |  | (43) |
﻿Amortization of: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
﻿Net loss |  |  | 17 |  |  | 22 |  |  |  | 34 |  |  | 44 |  |  |  | 5 |  |  | 5 |  |  |  | 11 |  |  | 11 |
﻿Prior service cost (credit) |  |  | 1 |  |  | 1 |  |  |  | 2 |  |  | 1 |  |  |  | (10) |  |  | (10) |  |  |  | (20) |  |  | (20) |
﻿Net periodic cost (credit) |  | $ | 13 |  | $ | 25 |  |  | $ | 26 |  | $ | 51 |  |  | $ | (9) |  | $ | (6) |  |  | $ | (18) |  | $ | (12) |
﻿

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- Definition The entire disclosure for pension and other postretirement benefits. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e2410-114920 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 60 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6414203&loc=d3e39675-114964 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 60 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=66047640&loc=d3e39622-114963 + Details
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