Shareholders' Equity - Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ (62.8)
Other comprehensive (loss) income before reclassifications, net of tax (1)	(20.0)	[1]
Amounts reclassified from accumulated other comprehensive loss, net of tax	(2.0)
Net current period other comprehensive income (loss)	(22.0)
Ending Balance	(84.8)
Tax on unrealized gains on derivative financial instruments	3.1
Liability adjustments for defined benefit plans	1.7
Gains (Losses) on Derivative Financial Instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	2.4
Other comprehensive (loss) income before reclassifications, net of tax (1)	6.1	[1]
Amounts reclassified from accumulated other comprehensive loss, net of tax	(3.4)
Net current period other comprehensive income (loss)	2.7
Ending Balance	5.1
Defined Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(11.6)
Other comprehensive (loss) income before reclassifications, net of tax (1)	(10.4)	[1]
Amounts reclassified from accumulated other comprehensive loss, net of tax	1.4
Net current period other comprehensive income (loss)	(9.0)
Ending Balance	(20.6)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(53.6)
Other comprehensive (loss) income before reclassifications, net of tax (1)	(15.7)	[1]
Amounts reclassified from accumulated other comprehensive loss, net of tax	0
Net current period other comprehensive income (loss)	(15.7)
Ending Balance	$ (69.3)

[1] Income tax expense of $3.1 million was recorded for unrealized gains on derivative financial instruments and income tax benefit of $1.7 million for liability adjustments for defined benefit plans for the year ended December 31, 2014.