Financing Arrangements and Debt (Details)	6 Months Ended
	Jun. 30, 2016 USD ($)
Line of Credit Facility [Line Items]
Capital lease duration	25 years
Capital lease payment duration	15 years
Capital lease obligations, current	$ 20,000,000
Capital lease obligations, noncurrent	202,700,000
Committed Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit facility maximum borrowing capacity	$ 2,000,000,000
Credit facility, maturity date	Jun. 01, 2017
Credit facility interest rate above LIBOR	1.45%
Line of credit facility fee	0.30%
Amount outstanding	$ 0
Uncommitted Credit Facilities [Member]
Line of Credit Facility [Line Items]
Amount outstanding	0
Current borrowing capacity	195,000,000
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Amount outstanding	$ 88,000,000