Foreign Exchange - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Foreign Currency [Abstract]
Net foreign exchange transaction gains (losses)	$ 0.6	$ (1.3)	$ 53.0	$ (1.3)