XML 44 R26.htm IDEA: XBRL DOCUMENT
v3.21.1

Investments (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2021
Investments [Abstract] |
Amortized cost, gross unrealized gains and losses and fair value of fixed income securities | Our fixed income securities classified as available-for-sale at March 31, 2021 and December 31, 2020 are shown in tables 7.1a and 7.1b below.
Details of fixed income securities by category as of March 31, 2021
Table | 7.1a |  |  |  |  |  |  |  |  |  |
(In thousands) |  | Amortized Cost |  | Allowance for Expected Credit Loss |  | Gross Unrealized Gains |  | Gross Unrealized (Losses) |  | Fair Value
U.S. Treasury securities and obligations of U.S. government corporations and agencies |  | $ | 252,806 |  |  | $ | — |  |  | $ | 873 |  |  | $ | (222) |  |  | $ | 253,457 |
Obligations of U.S. states and political subdivisions |  | 2,249,876 |  |  | — |  |  | 132,869 |  |  | (14,727) |  |  | 2,368,018 |
Corporate debt securities |  | 2,771,839 |  |  | — |  |  | 104,279 |  |  | (14,990) |  |  | 2,861,128 |
ABS |  | 185,394 |  |  | (31) |  |  | 2,000 |  |  | (222) |  |  | 187,141 |
RMBS |  | 432,148 |  |  | — |  |  | 5,270 |  |  | (1,410) |  |  | 436,008 |
CMBS |  | 317,055 |  |  | — |  |  | 12,875 |  |  | (2,080) |  |  | 327,850 |
CLOs |  | 372,417 |  |  | — |  |  | 966 |  |  | (56) |  |  | 373,327 |
Foreign government debt |  | 4,485 |  |  | — |  |  | — |  |  | (96) |  |  | 4,389 |
Total fixed income securities |  | $ | 6,586,020 |  |  | $ | (31) |  |  | $ | 259,132 |  |  | $ | (33,803) |  |  | $ | 6,811,318 |
Details of fixed income securities by category as of December 31, 2020
Table | 7.1b |  |  |  |  |  |  |  |  |  |
(In thousands) |  | Amortized Cost |  | Allowance for Expected Credit Losses |  | Gross Unrealized Gains |  | Gross Unrealized (Losses) (1) |  | Fair Value
U.S. Treasury securities and obligations of U.S. government corporations and agencies |  | 264,531 |  |  | — |  |  | $ | 1,164 |  |  | $ | (2) |  |  | $ | 265,693 |
Obligations of U.S. states and political subdivisions |  | 2,083,568 |  |  | — |  |  | 166,557 |  |  | (256) |  |  | 2,249,869 |
Corporate debt securities |  | 2,690,860 |  |  | — |  |  | 155,156 |  |  | (1,728) |  |  | 2,844,288 |
ABS |  | 203,807 |  |  | (49) |  |  | 2,946 |  |  | (18) |  |  | 206,686 |
RMBS |  | 425,532 |  |  | — |  |  | 6,472 |  |  | (838) |  |  | 431,166 |
CMBS |  | 312,572 |  |  | — |  |  | 16,055 |  |  | (1,125) |  |  | 327,502 |
CLOs |  | 310,616 |  |  | — |  |  | 566 |  |  | (692) |  |  | 310,490 |
Foreign government debt |  | 4,485 |  |  | — |  |  | 224 |  |  | — |  |  | 4,709 |
Commercial paper |  | 21,193 |  |  | — |  |  | — |  |  | — |  |  | 21,193 |
Total fixed income securities |  | $ | 6,317,164 |  |  | $ | (49) |  |  | $ | 349,140 |  |  | $ | (4,659) |  |  | $ | 6,661,596 |
Amortized cost and fair values of fixed income securities by contractual maturity | The amortized cost and fair values of fixed income securities at March 31, 2021, by contractual maturity, are shown in table 7.2 below. Actual maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Because most ABS, RMBS, CMBS, and CLOs provide for periodic payments throughout their lives, they are listed in separate categories.
Fixed income securities maturity schedule
Table | 7.2 |  |  |  |
|  | March 31, 2021
(In thousands) |  | Amortized cost |  | Fair Value
Due in one year or less |  | $ | 372,100 |  |  | $ | 376,608 |
Due after one year through five years |  | 1,964,439 |  |  | 2,033,836 |
Due after five years through ten years |  | 1,463,849 |  |  | 1,538,784 |
Due after ten years |  | 1,478,618 |  |  | 1,537,764 |
|  | 5,279,006 |  |  | 5,486,992 |
ABS |  | 185,394 |  |  | 187,141 |
RMBS |  | 432,148 |  |  | 436,008 |
CMBS |  | 317,055 |  |  | 327,850 |
CLOs |  | 372,417 |  |  | 373,327 |
Total as of March 31, 2021 |  | $ | 6,586,020 |  |  | $ | 6,811,318 |
Cost and fair value of investments in equity securities | The cost and fair value of investments in equity securities at March 31, 2021 and December 31, 2020 are shown in tables 7.3a and 7.3b below.
Details of equity security investments as of March 31, 2021
Table | 7.3a |  |  |  |  |  |  |  |
(In thousands) |  | Cost |  | Gross Gains |  | Gross Losses |  | Fair Value
Equity securities |  | $ | 15,052 |  |  | $ | 302 |  |  | $ | (35) |  |  | $ | 15,319 |
Details of equity security investments as of December 31, 2020
Table | 7.3b |  |  |  |  |  |  |  |
(In thousands) |  | Cost |  | Gross Gains |  | Gross Losses |  | Fair Value
Equity securities |  | $ | 17,522 |  |  | $ | 695 |  |  | $ | (2) |  |  | $ | 18,215 |
Aging of the fair values of securities in an unrealized loss position | Tables 7.4a and 7.4b below summarize, for all available-for-sale investments in an unrealized loss position at March 31, 2021 and December 31, 2020, the aggregate fair value and gross unrealized loss by the length of time those securities have been continuously in an unrealized loss position. The fair value amounts reported in tables 7.4a and 7.4b are estimated using the process described in Note 8 - “Fair Value Measurements” to these consolidated financial statements and in Note 3 - “Significant Accounting Policies” of the notes to the consolidated financial statements in our 2020 Annual Report on Form 10-K.
Unrealized loss aging for securities by type and length of time as of March 31, 2021
Table | 7.4a |  |  |  |  |  |  |  |  |  |  |  |
|  | Less Than 12 Months |  | 12 Months or Greater |  | Total
(In thousands) |  | Fair Value |  | Unrealized Losses |  | Fair Value |  | Unrealized Losses |  | Fair Value |  | Unrealized Losses
U.S. Treasury securities and obligations of U.S. government corporations and agencies |  | $ | 57,006 |  |  | $ | (222) |  |  | $ | — |  |  | $ | — |  |  | $ | 57,006 |  |  | $ | (222) |
Obligations of U.S. states and political subdivisions |  | 522,476 |  |  | (14,727) |  |  | — |  |  | — |  |  | 522,476 |  |  | (14,727) |
Corporate debt securities |  | 580,879 |  |  | (14,990) |  |  | — |  |  | — |  |  | 580,879 |  |  | (14,990) |
ABS |  | 50,656 |  |  | (222) |  |  | — |  |  | — |  |  | 50,656 |  |  | (222) |
RMBS |  | 127,663 |  |  | (1,387) |  |  | 3,254 |  |  | (23) |  |  | 130,917 |  |  | (1,410) |
CMBS |  | 70,193 |  |  | (749) |  |  | 13,150 |  |  | (1,331) |  |  | 83,343 |  |  | (2,080) |
CLOs |  | 55,161 |  |  | (15) |  |  | 24,510 |  |  | (41) |  |  | 79,671 |  |  | (56) |
Foreign government debt |  | 4,389 |  |  | (96) |  |  | — |  |  | — |  |  | 4,389 |  |  | (96) |
Total |  | $ | 1,468,423 |  |  | $ | (32,408) |  |  | $ | 40,914 |  |  | $ | (1,395) |  |  | $ | 1,509,337 |  |  | $ | (33,803) |
Unrealized loss aging for securities by type and length of time as of December 31, 2020
Table | 7.4b |  |  |  |  |  |  |  |  |  |  |  |
|  |  | Less Than 12 Months |  | 12 Months or Greater |  | Total
(In thousands) |  | Fair Value |  | Unrealized Losses |  | Fair Value |  | Unrealized Losses |  | Fair Value |  | Unrealized Losses
U.S. Treasury securities and obligations of U.S. government corporations and agencies |  | $ | 2,690 |  |  | $ | (2) |  |  | $ | — |  |  | $ | — |  |  | $ | 2,690 |  |  | $ | (2) |
Obligations of U.S. states and political subdivisions |  | 31,416 |  |  | (256) |  |  | — |  |  | — |  |  | 31,416 |  |  | (256) |
Corporate debt securities |  | 44,968 |  |  | (1,728) |  |  | — |  |  | — |  |  | 44,968 |  |  | (1,728) |
ABS |  | 14,929 |  |  | (18) |  |  | — |  |  | — |  |  | 14,929 |  |  | (18) |
RMBS |  | 98,409 |  |  | (773) |  |  | 3,566 |  |  | (65) |  |  | 101,975 |  |  | (838) |
CMBS |  | 13,212 |  |  | (789) |  |  | 2,799 |  |  | (336) |  |  | 16,011 |  |  | (1,125) |
CLOs |  | 95,287 |  |  | (261) |  |  | 73,904 |  |  | (431) |  |  | 169,191 |  |  | (692) |
Total |  | $ | 300,911 |  |  | $ | (3,827) |  |  | $ | 80,269 |  |  | $ | (832) |  |  | $ | 381,180 |  |  | $ | (4,659) |

X
- Definition Tabular disclosure of investments in equity securities. + References No definition available. + Details
Name: | mtg_EquitySecuritiesTableTextBlock
Namespace Prefix: | mtg_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of maturities of an entity's investments as well as any other information pertinent to the investments. + References No definition available. + Details
Name: | us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition For all investments in an unrealized loss position, including those for which other-than-temporary impairments have not been recognized in earnings (including investments for which a portion of an other-than-temporary impairment has been recognized in other comprehensive income), a tabular disclosure of the aggregate related fair value of investments with unrealized losses and the aggregate amount of unrealized losses (that is, the amount by which amortized cost basis exceeds fair value). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27290-111563 + Details
Name: | us-gaap_ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration