Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		69 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Sep. 30, 2012	Jan. 31, 2014
Loss Contingencies [Line Items]
Purchase obligation	$ 619
Deemed repatriation taxes	892
Net revenues	1,156	$ 1,175
GSA Schedule Contract
Loss Contingencies [Line Items]
Net revenues			$ 222
GSA initial analysis of damage exposure				$ 145
GSA Schedule Contract | Minimum
Loss Contingencies [Line Items]
Estimated loss	$ 25