Subsequent Events (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions				1 Months Ended	3 Months Ended
	Apr. 28, 2016	Apr. 01, 2016	Jan. 27, 2016	May. 09, 2016	Mar. 31, 2016	Mar. 31, 2015
Subsequent Event [Line Items]
Cash dividends declared per common stock (in dollars per share)			$ 0.1		$ 0.10	$ 0.10
Common stock repurchased under stock repurchase program average purchase price (in dollars per share)					$ 23.89	$ 23.05
Stock repurchased and retired (in shares)					3.1	17.4
2014 Stock Repurchase Program [Member]
Subsequent Event [Line Items]
Stock repurchase program, remaining authorized repurchase amount					$ 457.5
Subsequent Event [Member]
Subsequent Event [Line Items]
Cash dividends declared per common stock (in dollars per share)	$ 0.1
Subsequent Event [Member] | 2014 Stock Repurchase Program [Member]
Subsequent Event [Line Items]
Shares repurchased, in shares				3.8
Shares repurchased, value				$ 88.0
Common stock repurchased under stock repurchase program average purchase price (in dollars per share)				$ 23.16
Stock repurchased and retired (in shares)				2.8
Stock repurchase program, remaining authorized repurchase amount				$ 369.6
Subsequent Event [Member] | BTI Systems, Inc [Member]
Subsequent Event [Line Items]
Payments to acquire business		$ 65.0
Business combination, liabilities repaid		$ 23.9