Commitments and Contingencies (Lease Obligations) (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Capital Leased Assets [Line Items]
Rent expense	$ 53.1	$ 34.7	$ 26.6
Land, Buildings and Improvements [Member] | Los Gatos Buildings [Member]
Capital Leased Assets [Line Items]
Total costs of buildings and improvements	40.7
Capital lease obligations	29.2
Capital leases, future minimum payments due	18.5
Capital lease financing obligation under extended lease term	21.8
Land, Buildings and Improvements [Member] | Los Gatos Buildings Expanded Site and Los Angeles [Member]
Capital Leased Assets [Line Items]
Operating leases, future minimum payments due	$ 530.2