SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS Valuation and Qualifying Accounts (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 14	$ 12	$ 19
Provision/reversals Charged to Costs & Expenses	4	2	(6)
Charged to Other Accounts	0	0	0
Deductions	0	0	(1)
Balance at End of Period	18	14	12
Deferred tax valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	39	32	26
Provision/reversals Charged to Costs & Expenses	6	7	6
Charged to Other Accounts	0	0	0
Deductions	0	0	0
Balance at End of Period	$ 45	$ 39	$ 32