Fair Value Measurements - Schedule of Effect of Cash Flow Hedge Accounting on Consolidated Statement of Operations (Detail) - Interest Expense - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Interest expense (Location in the consolidated statement of operations in which the effects of cash flow hedges are recorded)	$ 397	$ 394	$ 374
Amount of (gain)/loss reclassified from accumulated other comprehensive income/(loss) into income, net of tax	$ (7)	$ (5)	$ 3