Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions				3 Months Ended
	May. 09, 2016	Mar. 28, 2016	Feb. 24, 2016	Mar. 31, 2016	Mar. 31, 2015
Dividends Payable [Line Items]
Dividends per share (in dollars per share)			$ 0.16	$ 0.16	$ 0.13
Cash payment amount		$ 3.8		$ 3.8	$ 3.1
Common stock available for future share repurchases, amount				$ 9.7
Common stock repurchased, number of shares repurchased				22,617	48,892
Common stock repurchased, average price per share (in dollars per share)				$ 77.37	$ 61.36
Common stock repurchased, total repurchase costs				$ 1.8	$ 3.0
Subsequent Event
Dividends Payable [Line Items]
Dividends per share (in dollars per share)	$ 0.16