Income Taxes (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Income Tax Contingency [Line Items]
Tax benefit from final audit settlement with IRS			$ 3.5
Tax benefit recognized on release of net state and local tax reserves	1.5		1.8
Additions for tax positions related to the current year			3.1	2.9
Additions for tax positions of prior years			0	15.1
Reductions for tax positions of prior years			1.1	0.1
Unrecognized tax benefits including interest and penalties that would affect the Company's effective tax rate if recognized	15.9	18.8	15.9	18.8
Total accrued interest and penalties	11.3		11.3		13.3
Increase (decrease) in tax expenses due to uncertain tax position	(1.3)	(0.3)	(2.1)	1.5
Lapse in Statute of Limitations
Income Tax Contingency [Line Items]
Reasonably possible change to unrecognized tax benefits within twelve months	7.8		7.8
Anticipated Settlement With Taxing Authorities
Income Tax Contingency [Line Items]
Reasonably possible change to unrecognized tax benefits within twelve months	$ 26.5		$ 26.5
Swiss subsidiary
Income Tax Contingency [Line Items]
Number of subsidiaries			2
General period of statute of limitations in Switzerland			5 years
Extended period of statute of limitations in Switzerland			15 years