Common Stock Repurchase Program - Additional Information (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	0 Months Ended		3 Months Ended	12 Months Ended	0 Months Ended
	Apr. 28, 2014	Apr. 23, 2014	Mar. 31, 2015	Dec. 31, 2014	Jul. 29, 2014	Apr. 28, 2015	Jan. 31, 2015
Share Repurchases [Line Items]
Repurchase of common stock, common stock authorized		$ 300.0					$ 100.0
Stock repurchase program, authorized amount for next twelve months		100.0
Accelerated share repurchase, contracted amount of repurchase	70.0
Stock Repurchased During Period, Shares			0.03	0.60
Stock Repurchased During Period, Average Price Per Share			$ 57.49	$ 50.93
Stock Repurchased During Period, Value			1.8	28.2
Stock Repurchase Program, Remaining Authorized Repurchase Amount			200.0
Accelerated Share Repurchase Program [Member]
Share Repurchases [Line Items]
Treasury Stock, Shares, Acquired					1.4
Share Repurchases Price Paid Per Share					$ 51.46
Subsequent Event
Share Repurchases [Line Items]
Accelerated share repurchase, contracted amount of repurchase						70.0
Payments under accelerated share repurchase agreement						$ 70.0
Treasury Stock, Shares, Acquired						0.8