Commitments and Contingencies (Leases) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Commitments and Contingencies Disclosure [Abstract]
Total rentals, net of sublease rentals	$ 958	$ 850	$ 735
Future total rentals on noncancellable operating leases	946
2014	282
2015	215
2016	156
2017	83
2018	56
Thereafter	$ 154