Goodwill - Changes in Goodwill (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2025 USD ($)
Goodwill [Line Items]
Balance at January 1, 2025	$ 3,767
Adjustments to purchase price allocations	10
Balance at June 30, 2025	3,777
East Group
Goodwill [Line Items]
Balance at January 1, 2025	1,031
Adjustments to purchase price allocations	0
Balance at June 30, 2025	1,031
West Group
Goodwill [Line Items]
Balance at January 1, 2025	2,736
Adjustments to purchase price allocations	10
Balance at June 30, 2025	$ 2,746