Income Taxes (Details Textual) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) subsidiary	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Income Tax Examination [Line Items]
Additions for tax positions related to the current year			$ 4.1	$ 3.7
Reductions for tax positions of prior years			0.1	0.1
Unrecognized tax benefits including interest and penalties that would affect the Company's effective tax rate if recognized	$ 15.0	$ 14.2	15.0	14.2
Total accrued interest and penalties	12.4		12.4		$ 11.6
Increase in income tax expense related to interest and penalties on unrecognized tax benefits	$ 0.3	$ 0.2	0.7	0.6
Federal and state tax authorities
Income Tax Examination [Line Items]
Additions for tax positions related to the current year			4.1	3.7
State tax authorities
Income Tax Examination [Line Items]
Reductions for tax positions of prior years			$ 0.1	$ 0.1
Subsidiaries | Foreign tax authority
Income Tax Examination [Line Items]
Number of subsidiaries | subsidiary			2
Number of subsidiaries, holding companies | subsidiary			1
Swiss subsidiary
Income Tax Examination [Line Items]
General period of statute of limitations in Switzerland			5 years
Extended period of statute of limitations in Switzerland			15 years