Schedule II - Valuation and Qualifying Accounts (Detail) - Allowances for Uncollectible Accounts and Sales Returns and Allowances [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 89	$ 120	$ 209
Charges to Costs and Expenses	0	0	0
Deductions to Allowances for Uncollectible Accounts	0	0	0
Charges to (Deductions from) Other Accounts	4	(31)	(89)
Balance at End of Year	$ 93	$ 89	$ 120