Debt (Revolving Facility) (Narrative) (Details) - Line of Credit - Revolving Facility - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Jun. 19, 2015	Dec. 19, 2014
Line of Credit Facility [Line Items]
Revolving Credit, maximum borrowing capacity			$ 1,650.0
Line of Credit Facility, Fair Value of Amount Outstanding		$ 0.0
Line of Credit Facility, Interest Rate During Period	1.325%
Line of Credit Facility, Commitment Fee Percentage	0.175%
Subfacility for Letters of Credit [Member]
Line of Credit Facility [Line Items]
Revolving Credit, maximum borrowing capacity				$ 150.0
Subfacility for Swing Line Borrowings [Member]
Line of Credit Facility [Line Items]
Revolving Credit, maximum borrowing capacity				$ 125.0