Subsequent Events (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions				1 Months Ended		3 Months Ended		6 Months Ended
	Jul. 26, 2016	Apr. 26, 2016	Jan. 27, 2016	Aug. 04, 2016	Jul. 31, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Subsequent Event [Line Items]
Cash dividends declared per common stock (in dollars per share)		$ 0.1	$ 0.1			$ 0.1	$ 0.1	$ 0.2	$ 0.2
2014 Stock Repurchase Program [Member]
Subsequent Event [Line Items]
Common stock repurchased under stock repurchase program average purchase price (in dollars per share)						$ 23.08	$ 25.83	$ 23.37	$ 24.64
Stock repurchased and retired (in shares)						5.5	23.2	8.6	40.6
Stock repurchase program, remaining authorized repurchase amount						$ 332.1		$ 332.1
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				0.9
Shares repurchased, value				$ 20.0
Common stock repurchased under stock repurchase program average purchase price (in dollars per share)				$ 22.42
Stock repurchase program, remaining authorized repurchase amount				$ 312.1
Aurrion, Inc | Subsequent Event [Member]
Subsequent Event [Line Items]
Consideration for business acquisition					$ 165.0