Schedule of Statutory Accounting Practices (Detail) - Domestic subsidiaries - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statutory Accounting Practices [Line Items]
Combined statutory net income (loss)	$ 1,276	$ (104)	$ 610
Combined statutory capital and surplus	7,769	7,384
Life insurance subsidiaries, excluding captive life reinsurance subsidiaries
Statutory Accounting Practices [Line Items]
Combined statutory net income (loss)	276	654	197
Combined statutory capital and surplus	3,082	2,945
Mortgage insurance subsidiaries
Statutory Accounting Practices [Line Items]
Combined statutory net income (loss)	747	593	404
Combined statutory capital and surplus	4,687	4,439
Combined statutory net income, excluding captive reinsurance subsidiaries
Statutory Accounting Practices [Line Items]
Combined statutory net income (loss)	1,023	1,247	601
Captive life reinsurance subsidiaries
Statutory Accounting Practices [Line Items]
Combined statutory net income (loss)	253	(1,351)	$ 9
Combined statutory capital and surplus	$ 96	$ 98

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.

No definition available.

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The amount of statutory capital and surplus (stockholders' equity) as of the balance sheet date using prescribed or permitted statutory accounting practices (rather than GAAP, if different) of the state or country.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(23)(c))
-URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 505
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=6486098&loc=d3e24708-158529

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- Definition

Amount of net income for the period determined using accounting principles prescribed or permitted by insurance regulators.

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