Equity Narratives (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
	Apr. 25, 2018	Mar. 31, 2018
Subsequent Event [Line Items]
Treasury Stock, Shares, Acquired		3,095,554
Treasury Stock, Value, Acquired, Par Value Method		$ 118.8
Treasury Stock Acquired, Average Cost Per Share		$ 38.38
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 351.4
Subsequent Event [Member]
Subsequent Event [Line Items]
Treasury Stock, Shares, Acquired	667,800
Treasury Stock, Value, Acquired, Par Value Method	$ 25.5
Treasury Stock Acquired, Average Cost Per Share	$ 38.12
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 325.9