Schedule II - Valuation Accounts and Reserves - Valuation Accounts and Reserves (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Doubtful Accounts [Member]
Balance at beginning of period	$ 48	$ 47	$ 28
Additions	11	1	19
Net deductions and other
Balance at end of period	59	48	47
Valuation Allowance of Deferred Tax Assets [Member]
Balance at beginning of period	238	298	286
Additions	55	30	186
Net deductions and other	23	90	174
Balance at end of period	270	238	298
Accumulated Amortization of Purchased Intangible Assets [Member]
Balance at beginning of period	265	216	185
Additions	64	49	31
Net deductions and other	4
Balance at end of period	325	265	216
Business Restructuring Reserves [Member]
Balance at beginning of period	3	44	44
Additions	15		49
Net deductions and other	13	41	49
Balance at end of period	$ 5	$ 3	$ 44