Income Taxes - Income Tax Reconciliation (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Tax at statutory U.S. tax rate	$ (38.3)	$ (8.1)	$ (113.2)
State income taxes, net of federal benefit	(3.2)	(0.2)	(6.3)
Net effect of international operations	1.1	3.1	25.0
Settlement of UK pension plan	0	(2.3)	0
Valuation allowances	22.9	(3.2)	89.2
Tax on unremitted earnings of foreign subsidiaries	15.9	0	0
U.S. tax on foreign earnings	4.7	6.2	3.9
Stock-based compensation	2.1	3.1	2.4
Uncertain tax positions	(1.2)	2.2	0.3
Goodwill impairment	10.7	0	0
Capital losses	(11.4)	0	0
Other	(0.2)	0.6	0.1
Income tax provision	$ 3.1	$ 1.4	$ 1.4