Commitments and Contingencies (Future Minimum Operating Lease Payments) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating leases, rent expense, minimum rentals	$ 135	$ 175	$ 122
Real Estate Leases [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2014	98
2015	87
2016	72
2017	54
2018	35
Thereafter	67
Total	413
Non-Rental Equipment Leases [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2014	28
2015	29
2016	22
2017	21
2018	19
Thereafter	16
Total	$ 135