Depreciation and Amortization by Type (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Depreciation And Amortization By Type [Line Items]
Depreciation And Amortization	$ 597	$ 560	$ 345
Future Amortization Expense Year One	410
Future Amortization Expense Year Two	327
Future Amortization Expense Year Three	253
Future Amortization Expense Year Four	167
Future Amortization Expense Year Five	133
Internal-use software [Member]
Depreciation And Amortization By Type [Line Items]
Depreciation And Amortization	225	209	187
Other property and equipment [Member]
Depreciation And Amortization By Type [Line Items]
Depreciation And Amortization	160	144	117
Assets Recorded under Capital Leases [Member]
Depreciation And Amortization By Type [Line Items]
Depreciation And Amortization	16
Other Intangibles [Member]
Depreciation And Amortization By Type [Line Items]
Depreciation And Amortization	193	205	41
Value Of Business Acquired [Member]
Depreciation And Amortization By Type [Line Items]
Depreciation And Amortization	$ 19	$ 2	$ 0