Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 87	$ 74	$ 77
Charged to Costs and Expenses	10	16	33
Valuation Allowances and Reserves, Reserves of Businesses Acquired	0	31	4
Deductions	(46)	(34)	(40)
Balance at End of Year	$ 51	$ 87	$ 74