Credit Facilities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Availability under Revolving Credit Facility [Abstract]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,200
Line of Credit Facility, Amount Outstanding	$ 629	$ 548
Foreign Subsidiaries [Member]
Credit Facilities Interest and Fees [Abstract]
Guarantee Percent	65.00%
Fiscal Year 2016 [Member]
Credit Facilities Repayment Terms [Abstract]
Annual Remaining Amortization	$ 4
Fiscal Year 2017 [Member]
Credit Facilities Repayment Terms [Abstract]
Annual Remaining Amortization	5
Fiscal Year 2018 [Member]
Credit Facilities Repayment Terms [Abstract]
Annual Remaining Amortization	5
Fiscal Year 2019 [Member]
Credit Facilities Repayment Terms [Abstract]
Annual Remaining Amortization	5
Fiscal Year 2020 [Member]
Credit Facilities Repayment Terms [Abstract]
Annual Remaining Amortization	181
Revolving Credit Facility [Member]
Availability under Revolving Credit Facility [Abstract]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,000
Line of Credit Facility, Expiration Date	Apr. 10, 2020
Line of Credit Facility, Amount Outstanding	$ 429	$ 348
Letters of Credit Outstanding, Amount	157
Line of Credit Facility, Remaining Borrowing Capacity	$ 414