Borrowing Arrangements (Derivatives and Hedging (Details) - USD ($)	1 Months Ended
	Jul. 31, 2016	Feb. 13, 2017	Dec. 31, 2016	Sep. 30, 2016	Feb. 29, 2016
Derivative [Line Items]
Variable rate debt amount			$ 1,700,000,000
Derivative notional amount	$ 225,000,000
Fixed rate debt amount			9,500,000,000
Debt instrument, face amount					$ 200,000,000
Interest rate					1.132%
Derivative gain	$ 1,900,000
Senior Notes Due 2026 3.25%
Derivative [Line Items]
Interest rate				3.25%
Swap | Variable Rate Debt
Derivative [Line Items]
Derivative notional amount			150,800,000
Swap | Fixed Rate Debt
Derivative [Line Items]
Derivative notional amount			$ 236,500,000
Subsequent Event
Derivative [Line Items]
Derivative notional amount		$ 200,000,000
Subsequent Event | Senior Notes Due 2026 3.25%
Derivative [Line Items]
Weighted interest rate		2.33%