Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Effective income tax rate (percent)	37.90%	38.40%
Gross unrecognized tax benefit	$ 4.2		$ 3.9
Expected change in unrecognized tax benefits	1.5
Accrued interest on income taxes	5.0		4.9
Accrued penalties on income taxes, less than	$ 0.1		$ 0.1