Derivative Instruments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Intercompany debt designated as a non-derivative net investment hedging instrument	$ 13.2		$ 13.2	$ 15.8
Gain (loss) currency translation adjustment	$ 1.8	$ 0.7
Foreign Currency Derivatives
Derivative [Line Items]
Notional amounts of foreign currency derivatives				$ 20.0
Minimum | Foreign Currency Derivatives
Derivative [Line Items]
Derivative maturities			November 2015
Maximum | Foreign Currency Derivatives
Derivative [Line Items]
Derivative maturities			December 2015