XML 57 R37.htm IDEA: XBRL DOCUMENT
v3.22.4

Benefit Plans (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2022
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |
Components of net periodic benefit cost | The following tables 11.1, 11.2, and 11.3 provide the components of aggregate annual net periodic benefit cost for each of the years ended December 31, 2022, 2021, and 2020 and changes in the benefit obligation and the funded status of the pension, supplemental executive retirement and other postretirement benefit plans as recognized in the consolidated balance sheets as of December 31, 2022 and 2021.
Components of net periodic benefit cost
Table | 11.1 |  |  |  |  |  |  |  |  |  |  |  |
|  | Pension and Supplemental Executive Retirement Plans |  | Other Postretirement Benefits
(In thousands) |  | 12/31/2022 |  | 12/31/2021 |  | 12/31/2020 |  | 12/31/2022 |  | 12/31/2021 |  | 12/31/2020
Company Service Cost |  | $ | 7,153 |  |  | $ | 7,569 |  |  | $ | 7,342 |  |  | $ | 1,307 |  |  | $ | 1,508 |  |  | $ | 1,263 |
Interest Cost |  | 12,461 |  |  | 11,276 |  |  | 13,036 |  |  | 694 |  |  | 648 |  |  | 832 |
Expected Return on Assets |  | (18,064) |  |  | (20,657) |  |  | (22,139) |  |  | (10,502) |  |  | (8,863) |  |  | (7,407) |
Amortization of: |  |  |  |  |  |  |  |  |  |  |  |
Net Transition Obligation/(Asset) |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |
Net Prior Service Cost/(Credit) |  | (163) |  |  | (239) |  |  | (247) |  |  | 489 |  |  | 213 |  |  | 51 |
Net Losses/(Gains) |  | 5,726 |  |  | 5,490 |  |  | 6,578 |  |  | (3,103) |  |  | (1,697) |  |  | (783) |
Cost of Settlements and Curtailments |  | 13,801 |  |  | 6,012 |  |  | 10,369 |  |  | — |  |  | — |  |  | — |
Net Periodic Benefit Cost |  | $ | 20,914 |  |  | $ | 9,451 |  |  | $ | 14,939 |  |  | $ | (11,115) |  |  | $ | (8,191) |  |  | $ | (6,044) |
Development of funded status |
Development of funded status
Table | 11.2 |  |  |  |  |  |  |  |
|  | Pension and Supplemental Executive Retirement Plans |  | Other Postretirement Benefits
(In thousands) |  | 12/31/2022 |  | 12/31/2021 |  | 12/31/2022 |  | 12/31/2021
Actuarial Value of Benefit Obligations |  |  |  |  |  |  |  |
Measurement Date |  | 12/31/2022 |  | 12/31/2021 |  | 12/31/2022 |  | 12/31/2021
Accumulated Benefit Obligation |  | $ | 274,975 |  |  | $ | 390,747 |  |  | $ | 29,580 |  |  | $ | 25,635 |
Funded Status/Asset (Liability) on the Consolidated Balance Sheet |  |  |  |  |  |  |  |
Benefit Obligation |  | $ | (274,975) |  |  | $ | (391,698) |  |  | $ | (29,580) |  |  | $ | (25,635) |
Plan Assets at Fair Value |  | 250,674 |  |  | 391,555 |  |  | 111,154 |  |  | 140,839 |
Funded Status - Overfunded/Asset |  | N/A |  | N/A |  | $ | 81,574 |  |  | $ | 115,204 |
Funded Status - Underfunded/Liability |  | (24,301) |  |  | (143) |  |  | N/A |  | N/A
Accumulated other comprehensive (income) loss
Table | 11.3 |  |  |  |  |  |  |  |
|  | Pension and Supplemental Executive Retirement Plans |  | Other Postretirement Benefits
(In thousands) |  | 12/31/2022 |  | 12/31/2021 |  | 12/31/2022 |  | 12/31/2021
Net Actuarial (Gain)/Loss |  | $ | 89,711 |  |  | $ | 84,045 |  |  | $ | (13,781) |  |  | $ | (47,352) |
Net Prior Service Cost/(Credit) |  | 3,245 |  |  | (747) |  |  | 13,249 |  |  | 2,461 |
Net Transition Obligation/(Asset) |  | — |  |  | — |  |  | — |  |  | — |
Total at Year End |  | $ | 92,956 |  |  | $ | 83,298 |  |  | $ | (532) |  |  | $ | (44,891) |
Change in projected benefit obligation | Table 11.4 shows the changes in the projected benefit obligation for the years ended December 31, 2022 and 2021.
Change in projected benefit / accumulated benefit
Table | 11.4 |  |  |  |  |  |  |  |
|  | Pension and Supplemental Executive Retirement Plans |  | Other Postretirement Benefits
(In thousands) |  | 12/31/2022 |  | 12/31/2021 |  | 12/31/2022 |  | 12/31/2021
Benefit Obligation at Beginning of Year |  | $ | 391,698 |  |  | $ | 423,713 |  |  | $ | 25,635 |  |  | $ | 28,714 |
Company Service Cost |  | 7,153 |  |  | 7,569 |  |  | 1,307 |  |  | 1,508 |
Interest Cost |  | 12,461 |  |  | 11,276 |  |  | 694 |  |  | 648 |
Plan Participants' Contributions |  | — |  |  | — |  |  | 463 |  |  | 456 |
Net Actuarial (Gain)/Loss |  | (83,240) |  |  | (10,018) |  |  | (8,123) |  |  | (3,574) |
Benefit Payments from Fund |  | (13,165) |  |  | (12,866) |  |  | (1,504) |  |  | (1,963) |
Benefit Payments Paid Directly by Company |  | (114) |  |  | (362) |  |  | — |  |  | — |
Plan Amendments |  | 3,247 |  |  | 2 |  |  | 11,278 |  |  | — |
Curtailments |  | (352) |  |  | — |  |  | — |  |  | — |
Settlement Payments from Fund (1) |  | (42,713) |  |  | (27,616) |  |  | — |  |  | — |
Other Adjustment |  | — |  |  | — |  |  | (170) |  |  | (154) |
Benefit Obligation at End of Year |  | $ | 274,975 |  |  | $ | 391,698 |  |  | $ | 29,580 |  |  | $ | 25,635 |
(1)Represents lump sum payments from our pension plan to eligible participants, who were former employees with vested benefits.
Changes in fair value of plan assets and other comprehensive income (loss) | Tables 11.5 and 11.6 shows the changes in the fair value of the net assets available for plan benefits and changes in other comprehensive income (loss) for the years ended December 31, 2022 and 2021.
Change in plan assets
Table | 11.5 |  |  |  |  |  |  |  |
|  | Pension and Supplemental Executive Retirement Plans |  | Other Postretirement Benefits
(In thousands) |  | 12/31/2022 |  | 12/31/2021 |  | 12/31/2022 |  | 12/31/2021
Fair Value of Plan Assets at Beginning of Year |  | $ | 391,555 |  |  | $ | 411,245 |  |  | $ | 140,839 |  |  | $ | 119,024 |
Actual Return on Assets |  | (91,303) |  |  | 13,992 |  |  | (28,088) |  |  | 23,773 |
Company Contributions |  | 6,414 |  |  | 7,162 |  |  | — |  |  | — |
Plan Participants' Contributions |  | — |  |  | — |  |  | 463 |  |  | 456 |
Benefit Payments from Fund |  | (13,165) |  |  | (12,866) |  |  | (1,504) |  |  | (1,963) |
Benefit Payments Paid Directly by Company |  | (114) |  |  | (362) |  |  | — |  |  | — |
Settlement Payments from Fund |  | (42,713) |  |  | (27,616) |  |  | — |  |  | — |
Other Adjustment |  | — |  |  | — |  |  | (556) |  |  | (451) |
Fair Value of Plan Assets at End of Year |  | $ | 250,674 |  |  | $ | 391,555 |  |  | $ | 111,154 |  |  | $ | 140,839 |
Change in accumulated other comprehensive income (loss) ("AOCI") |  |  |  |  |  |
Table | 11.6 |  |  |  |  |  |  |  |
|  | Pension and Supplemental Executive Retirement Plans |  | Other Postretirement Benefits
(In thousands) |  | 12/31/2022 |  | 12/31/2021 |  | 12/31/2022 |  | 12/31/2021
AOCI in Prior Year |  | $ | 83,298 |  |  | $ | 97,911 |  |  | $ | (44,891) |  |  | $ | (27,892) |
Increase/(Decrease) in AOCI |  |  |  |  |  |  |  |
Recognized during year - Prior Service (Cost)/Credit |  | 745 |  |  | 239 |  |  | (489) |  |  | (213) |
Recognized during year - Net Actuarial (Losses)/Gains |  | (20,109) |  |  | (11,502) |  |  | 3,103 |  |  | 1,697 |
Occurring during year - Prior Service Cost |  | 3,247 |  |  | 2 |  |  | 11,277 |  |  | — |
Occurring during year - Net Actuarial Losses/(Gains) |  | 25,775 |  |  | (3,352) |  |  | 30,468 |  |  | (18,483) |
AOCI in Current Year |  | $ | 92,956 |  |  | $ | 83,298 |  |  | $ | (532) |  |  | $ | (44,891) |
Actuarial assumptions | The projected benefit obligations, net periodic benefit costs and accumulated postretirement benefit obligation for the plans were determined using the following weighted average assumptions.
Actuarial assumptions
Table | 11.7 |  |  |  |  |  |  |  |
|  | Pension and Supplemental Executive Retirement Plans |  | Other Postretirement Benefits
|  | 12/31/2022 |  | 12/31/2021 |  | 12/31/2022 |  | 12/31/2021
Weighted-Average Assumptions Used to Determine |  |  |  |  |  |  |  |
Benefit Obligations at year end |  |  |  |  |  |  |  |
1. Discount Rate |  | 5.60 | % |  | 3.05 | % |  | 5.60 | % |  | 2.85 | %
2. Rate of Compensation Increase |  | 3.00 | % |  | 3.00 | % |  | N/A |  | N/A
3. Cash balance interest crediting rate |  | 3.97 | % |  | 2.80 | % |  | N/A |  | N/A
Weighted-Average Assumptions Used to Determine |  |  |  |  |  |  |  |
Net Periodic Benefit Cost for Year |  |  |  |  |  |  |  |
1. Discount Rate |  | 3.70 | % |  | 2.80 | % |  | 2.85 | % |  | 2.35 | %
2. Expected Long-term Return on Plan Assets |  | 5.25 | % |  | 5.25 | % |  | 7.50 | % |  | 7.50 | %
3. Rate of Compensation Increase |  | 3.00 | % |  | 3.00 | % |  | N/A |  | N/A
Assumed Health Care Cost Trend Rates at year end |  |  |  |  |  |  |  |
1. Health Care Cost Trend Rate Assumed for Next Year |  | N/A |  | N/A |  | 7.00 | % |  | 6.50 | %
2. Rate to Which the Cost Trend Rate is Assumed to Decline (Ultimate Trend Rate) |  | N/A |  | N/A |  | 5.00 | % |  | 5.00 | %
3. Year That the Rate Reaches the Ultimate Trend Rate |  | N/A |  | N/A |  | 2031 |  | 2028
Year-end asset allocations of the plans | The year-end asset allocations of the plans are shown in table 11.8 below.
Plan assets
Table | 11.8 |  |  |  |  |  |  |  |
|  | Pension Plan |  | Other Postretirement Benefits
|  | 12/31/2022 |  | 12/31/2021 |  | 12/31/2022 |  | 12/31/2021
Equity Securities |  | 20 | % |  | 21 | % |  | 100 | % |  | 100 | %
Debt Securities |  | 80 | % |  | 79 | % |  | — | % |  | — | %
Total |  | 100 | % |  | 100 | % |  | 100 | % |  | 100 | %
Schedule of investment allocation strategies | The equity investments use combinations of mutual funds, ETFs, and pooled equity account structures focused on the following strategies:
Strategy |  | Objective |  | Investment types
Return seeking growth |  | Funded ratio improvement over the long term |  | ● | Global quality growth
|  | ● | Global low volatility
Return seeking bridge |  | Downside protection in the event of a declining equity market |  | ● | Enduring asset
|  | ● | Durable company
Minimum and maximum allocation ranges for fixed income securities and equity securities | The primary focus in developing asset allocation ranges for the portfolio is the assessment of the portfolio's investment objectives and the level of risk that is acceptable to obtain those objectives. To achieve these objectives the minimum and maximum allocation ranges for fixed income securities and equity securities are:
| Minimum |  | Maximum
Equities (long only) | 70 | % |  | 100 | %
Real estate | 0 | % |  | 15 | %
Commodities | 0 | % |  | 10 | %
Fixed income/Cash | 0 | % |  | 10 | %
Actual and estimated future contributions and actual and estimated future benefit payments | Expected future benefit payments from the plans are shown in Table 11.12 below.
Expected future benefit payments
Table | 11.12 |  |  |  |
|  | Pension and Supplemental Executive Retirement Plans |  | Other Postretirement Benefits
(In thousands) |  | 12/31/2022 |  | 12/31/2022
Current + 1 |  | 23,966 |  |  | 2,211 |
Current + 2 |  | 23,309 |  |  | 2,476 |
Current + 3 |  | 23,104 |  |  | 2,780 |
Current + 4 |  | 23,363 |  |  | 2,886 |
Current + 5 |  | 23,194 |  |  | 2,929 |
Current + 6 - 10 |  | 102,588 |  |  | 16,102 |
Pension Plan |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |
Schedule of fair value of plan assets | Tables 11.9a and 11.9b set forth by level, within the fair value hierarchy, the pension plan assets and related accrued investment income at fair value as of December 31, 2022 and 2021. There were no securities that used Level 3 inputs.
Pension plan assets at fair value as of December 31, 2022
Table | 11.9a |  |  |  |  |  |
(In thousands) |  | Level 1 |  | Level 2 |  | Total
Domestic mutual funds |  | $ | 67 |  |  | $ | — |  |  | $ | 67 |
U.S. government securities |  | 13,328 |  |  | — |  |  | 13,328 |
Corporate debt securities |  |  |  |  |  |
Corporate debt securities and other |  | — |  |  | 146,854 |  |  | 146,854 |
Non-government foreign debt securities |  | — |  |  | 20,793 |  |  | 20,793 |
Municipal bonds |  | — |  |  | 18,336 |  |  | 18,336 |
Pooled equity accounts |  | — |  |  | 51,296 |  |  | 51,296 |
Total Assets at fair value |  | $ | 13,395 |  |  | $ | 237,279 |  |  | $ | 250,674 |
Pension plan assets at fair value as of December 31, 2021
Table | 11.9b |  |  |  |  |  |
(In thousands) |  | Level 1 |  | Level 2 |  | Total
Domestic mutual funds |  | $ | 4,071 |  |  | $ | — |  |  | $ | 4,071 |
U.S. government securities |  | 32,947 |  |  | — |  |  | 32,947 |
Corporate debt Securities |  |  |  |  |  |
Corporate debt securities and other |  | — |  |  | 221,033 |  |  | 221,033 |
Non-government foreign debt securities |  | — |  |  | 34,103 |  |  | 34,103 |
Municipal bonds |  | — |  |  | 20,093 |  |  | 20,093 |
Pooled equity accounts |  | — |  |  | 79,308 |  |  | 79,308 |
Total Assets at fair value |  | $ | 37,018 |  |  | $ | 354,537 |  |  | $ | 391,555 |
Other Postretirement Benefit Plan |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |
Schedule of fair value of plan assets | Tables 11.10a and 11.10b set forth the other postretirement benefits plan assets at fair value as of December 31, 2022 and 2021. All are Level 1 assets.
Other postretirement benefits plan assets at fair value as of December 31, 2022
Table | 11.10a |  |
(In thousands) |  | Level 1
Domestic Mutual Funds |  | $ | 89,584 |
International Mutual Funds |  | 21,570 |
Total Assets at fair value |  | $ | 111,154 |
Other postretirement benefits plan assets at fair value as of December 31, 2021
Table | 11.10b |  |
(In thousands) |  | Level 1
Domestic Mutual Funds |  | $ | 112,770 |
International Mutual Funds |  | 28,069 |
Total Assets at fair value |  | $ | 140,839 |

X
- Definition Tabular disclosure of actual and estimated future contributions, and actual and estimated future benefit payments 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 No definition available. + Details
Name: | mtg_ActualAndEstimatedFutureContributionsAndActualAndEstimatedFutureBenefitPaymentsTableTextBlock
Namespace Prefix: | mtg_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of pension plans and/or other employee benefit plans': 1) actuarial value of benefit obligations; 2) funded status; and 3) accumulated other comprehensive income (loss) recognized as components of net periodic benefit cost, including the net gain (loss), net prior service cost or credit, and net transition asset or obligation. + References No definition available. + Details
Name: | mtg_DevelopmentOfFundedStatusTableTextBlock
Namespace Prefix: | mtg_
Data Type: | dtr-types: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 targeted minimum and maximum allocation ranges for fixed income securities and equity securities. + References No definition available. + Details
Name: | mtg_MinimumAndMaximumAllocationRangesForFixedIncomeSecuritiesAndEquitySecuritiesTableTextBlock
Namespace Prefix: | mtg_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule Of Changes In Fair Value Of Plan Assets and Other Comprehensive Income (Loss) + References No definition available. + Details
Name: | mtg_ScheduleOfChangesInFairValueOfPlanAssetsAndOtherComprehensiveIncomeLossTableTextBlock
Namespace Prefix: | mtg_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of Investment Allocation Strategies [Table Text Block] + References No definition available. + Details
Name: | mtg_ScheduleofInvestmentAllocationStrategiesTableTextBlock
Namespace Prefix: | mtg_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
Name: | us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of assumption used to determine benefit obligation and net periodic benefit cost of defined benefit plan. Includes, but is not limited to, discount rate, rate of compensation increase, expected long-term rate of return on plan assets and interest crediting rate. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
Name: | us-gaap_ScheduleOfAssumptionsUsedTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the change in the benefit obligation of pension plans and/or other employee benefit plans from the beginning to the end of the period, showing separately, if applicable, the effects of the following: service cost, interest cost, contributions by plan participants, actuarial gains and losses, foreign currency exchange rate changes, benefits paid, plan amendments, business combinations, divestitures, curtailments, settlements, and special and contractual termination benefits. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
Name: | us-gaap_ScheduleOfChangesInProjectedBenefitObligationsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of one or more of the entity's defined benefit pension plans or one or more other defined benefit postretirement plans, separately for pension plans and other postretirement benefit plans including the entity's schedule of fair value of plan assets for defined benefit or other postretirement plans. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2439-114920 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2410-114920 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2417-114920 + Details
Name: | us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types: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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
Name: | us-gaap_ScheduleOfNetBenefitCostsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |