Schedule II - Condensed Statements Of Cash Flows (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Investment income received	$ 77	$ 118	$ 176
Interest paid, net of interest converted to principal	(61)	(84)	(180)
Income taxes (paid) received	0	13	11
Net cash provided (used) by operating activities	511	(390)	(368)
Cash flows from investing activities:
Paydowns and maturities of available-for-sale investments	626	724	857
Purchases of investments at fair value	(206)	(179)	(151)
Sales, paydowns and maturities of investments at fair value	174	198	617
Sales, paydowns and maturities (purchases) of short-term investments, net	(99)	143	(157)
(Payments) proceeds for derivative settlements	(66)	(16)	(98)
Net cash provided (used) by investing activities	(61)	1,738	1,267
Cash flows from financing activities:
Proceeds from investment agreements	2	12	15
Principal paydowns of investment agreements	(2)	(48)	(25)
Net cash provided (used) by financing activities	(457)	(1,265)	(1,096)
Effect of exchange rate changes on cash and cash equivalents	0	1	0
Net increase (decrease) in cash and cash equivalents	(7)	84	(197)
Cash and cash equivalents—beginning of year	167	83	280
Cash and cash equivalents—end of year	160	167	83
Reconciliation of net income (loss) to net cash provided (used) by operating activities: [Abstract]
Net income (loss)	(445)	(578)	(359)
Change in: [Abstract]
Net (gains) losses on financial instruments at fair value and foreign exchange	(40)	(70)	(157)
Deferred income tax provision (benefit)	0	12	13
Other operating	22	47	30
Total adjustments to net income (loss)	956	188	(9)
Net cash provided (used) by operating activities	511	(390)	(368)
Parent Company [Member]
Cash flows from operating activities:
Investment income received	80	101	156
Operating expenses paid and other operating	(14)	(47)	(17)
Interest paid, net of interest converted to principal	(50)	(60)	(88)
Income taxes (paid) received	6	5	34
Net cash provided (used) by operating activities	22	(1)	85
Cash flows from investing activities:
Purchases of available-for-sale investments	(150)	(216)	(278)
Sales of available-for-sale investments	202	183	319
Paydowns and maturities of available-for-sale investments	20	41	179
Purchases of investments at fair value	(2)	(2)	5
Sales, paydowns and maturities of investments at fair value	3	2	0
Sales, paydowns and maturities (purchases) of short-term investments, net	(27)	137	(61)
(Payments) proceeds for derivative settlements	(17)	(16)	(98)
Return of capital from subsidiaries	11	0	0
Contributions (to) from subsidiaries, net	0	0	(14)
Net cash provided (used) by investing activities	40	129	52
Cash flows from financing activities:
Proceeds from investment agreements	2	12	15
Principal paydowns of investment agreements	(2)	(18)	(20)
Principal paydowns of long-term debt	0	(115)	(150)
Payments for affiliate loans	(81)	0	(19)
Restricted stock awards settlements	8	8	8
Net cash provided (used) by financing activities	(73)	(113)	(166)
Effect of exchange rate changes on cash and cash equivalents	0	0	0
Net increase (decrease) in cash and cash equivalents	(11)	15	(29)
Cash and cash equivalents—beginning of year	26	11	40
Cash and cash equivalents—end of year	15	26	11
Reconciliation of net income (loss) to net cash provided (used) by operating activities: [Abstract]
Net income (loss)	(445)	(578)	(359)
Change in: [Abstract]
Intercompany accounts receivable	(7)	(39)	(16)
Current income taxes	6	5	23
Equity in earnings of subsidiaries	465	450	333
Dividends from subsidiaries	60	81	134
Net (gains) losses on financial instruments at fair value and foreign exchange	(52)	67	57
Deferred income tax provision (benefit)	(3)	(4)	(88)
(Gains) losses on extinguishment of debt	(30)	0	1
Other operating	28	17	0
Total adjustments to net income (loss)	467	577	444
Net cash provided (used) by operating activities	$ 22	$ (1)	$ 85