Equity - Narrative (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Dec. 31, 2016	Dec. 31, 2015
Equity, Class of Treasury Stock [Line Items]
Anti-dilutive potential common shares excluded from reconciliation	5	3	5	3
Common stock repurchased (in shares)			7	6
Common stock repurchased			$ 516	$ 426	$ 426
Payments for Repurchase of Common Stock			$ 516	$ 426
Treasury stock
Equity, Class of Treasury Stock [Line Items]
Common stock repurchased (in shares)			7		6
Common stock repurchased			$ 516		$ 426
December 2015 Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount						$ 1,500
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 558		$ 558