Equity (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Summary of accumulated other comprehensive loss
Balance at the beginning of the period	$ (8.8)
Current year change	7.3
Balance at the end of the period	(1.5)
Deferred tax assets in accumulated other comprehensive income, pension liabilities	13.4	11.5
Deferred tax assets in accumulated other comprehensive income, unrealized loss on investments	0.1	0.1
Foreign Currency Translation Adjustment
Summary of accumulated other comprehensive loss
Balance at the beginning of the period	10.4
Current year change	10.6
Balance at the end of the period	21.0
Unrealized Loss on Investments, Net of Tax
Summary of accumulated other comprehensive loss
Balance at the beginning of the period	(0.4)
Current year change	0.2
Balance at the end of the period	(0.2)
Minimum Pension Liability, Net of Tax
Summary of accumulated other comprehensive loss
Balance at the beginning of the period	(18.8)
Current year change	(3.5)
Balance at the end of the period	$ (22.3)