Commitments and Contingencies (Lease Obligations) (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Capital Leased Assets [Line Items]
Rent expense	$ 107	$ 75	$ 53
Land, Buildings and Improvements | Los Gatos Buildings
Capital Leased Assets [Line Items]
Total costs of buildings and improvements	41
Capital lease obligations	28
Capital leases, future minimum payments due	11
Capital lease financing obligation under extended lease term	22
Land, Buildings and Improvements | Los Gatos Buildings Expanded Site and Los Angeles
Capital Leased Assets [Line Items]
Operating leases, future minimum payments due	$ 1,157