Comprehensive Income - Schedule of Changes in Balances of Each Component of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	$ (253)	$ 58
Other comprehensive income before reclassifications	(74)	296
Amounts reclassified from accumulated other comprehensive income	19	(15)
Income Tax Expense (Benefit)	(7)	(2)	$ (18)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	93	(310)
Ending Balance	(160)	(253)	58
Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(71)	154
Other comprehensive income before reclassifications	(31)	211
Amounts reclassified from accumulated other comprehensive income	21	(14)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	51	(225)
Ending Balance	(20)	(71)	154
Accumulated Translation Adjustment [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(184)	(100)
Other comprehensive income before reclassifications	(40)	85
Amounts reclassified from accumulated other comprehensive income	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	40	(85)
Ending Balance	(144)	(184)	(100)
Accumulated Gain (Loss), Financial Liability, Fair Value Option, Attributable to Parent [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(1)	(1)
Other comprehensive income before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	0	0
Ending Balance	(1)	(1)	(1)
Other Postretirement Benefits Plan [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	3	4
Other comprehensive income before reclassifications	(3)	0
Amounts reclassified from accumulated other comprehensive income	(1)	(1)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	2	(1)
Ending Balance	$ 5	$ 3	$ 4