Contract Assets and Contract Liabilities - Components of Net Contract Assets (Liabilities) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenue from Contract with Customer [Abstract]
Contract assets	$ 1,499	$ 1,349	$ 0
Contract liabilities — current	(607)	(565)	0
Contract liabilities — non-current	(30)	(28)	$ 0
Net contract assets (liabilities)	862	$ 756
Increase in contract assets	150
Increase in contract liability	44
Revenue recognized related to contract liabilities	$ 243