Accumulated Other Comprehensive Income (Loss) ("AOCI") - Components of AOCI (Detail) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Accumulated other comprehensive income (loss), Beginning balance			$ (150)				$ (150)
Amounts reclassified from accumulated other comprehensive income (loss)								$ 10
Net current-period other comprehensive income	$ (4)	$ 3	1	$ (11)	$ 1	$ 2
Accumulated other comprehensive income (loss), Ending balance	(150)						(150)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated other comprehensive income (loss), Beginning balance			(150)			(147)	(150)	(147)
Other comprehensive income (loss) before reclassifications							0	(18)
Amounts reclassified from accumulated other comprehensive income (loss)							0	10
Net current-period other comprehensive income	(4)	$ 3	$ 1	(11)	$ 1	$ 2	0	(8)
Accumulated other comprehensive income (loss), Ending balance	$ (150)			$ (155)			$ (150)	$ (155)