Comprehensive Income or Loss - Changes in Components (Details) $ in Millions	6 Months Ended
	Jun. 30, 2015 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31, 2014	$ (229.9)
Net unrealized loss arising during the period	(131.0)
Reclassification of net loss into earnings	1.5
Balance at June 30, 2015	(359.4)
Foreign currency translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31, 2014	(190.9)
Net unrealized loss arising during the period	(130.2)
Reclassification of net loss into earnings	0.0
Balance at June 30, 2015	(321.1)
Derivative instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31, 2014	(0.3)
Net unrealized loss arising during the period	(0.8)
Reclassification of net loss into earnings	0.2
Balance at June 30, 2015	(0.9)
Defined benefit plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31, 2014	(38.7)
Net unrealized loss arising during the period	0.0
Reclassification of net loss into earnings	1.3
Balance at June 30, 2015	$ (37.4)