SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance For Loss On Receivables
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 101	$ 137	$ 118
Acquired Balances	0	(39)	0
Charged (Credited) to Costs and Expenses	39	61	32
Charged to Other Accounts	19	(7)	28
Deductions or Write-offs	(41)	(51)	(41)
Balance at End of Period	118	101	137
Deferred Tax Asset Valuation Allowance
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	42	48	28
Acquired Balances	0	0	0
Charged (Credited) to Costs and Expenses	(7)	6	(20)
Charged to Other Accounts	0	0	0
Deductions or Write-offs	0	0	0
Balance at End of Period	$ 49	$ 42	$ 48