Income Tax Matters, Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income tax provision	$ 18.5	$ 15.1
Effective tax rate	34.00%	36.50%
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount	$ (1.6)	$ (0.7)
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Percent	(2.90%)	(1.70%)
Effective Income Tax Rate Reconciliation, Tax Contingency, State and Local, Amount	$ (0.4)	$ 0.3
Effective Income Tax Rate Reconciliation, Tax Contingency, State and Local, Percent	(0.80%)	0.70%
Gross unrecognized tax benefits that would impact effective tax rate	$ 1.8		$ 0.7