Supplementary Balance Sheet Information (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Statement of Financial Position [Abstract]
Derivative asset	$ 104	$ 47
Prepaid Expense, Noncurrent	67	86
Land Use Rights And Capitalized Development Costs Noncurrent	58	65
Accounts Receivable, Net, Noncurrent	27	17
Reinsurance Recoverables	22	10	9
Other Assets, Miscellaneous, Noncurrent	65	40
Other Assets, Noncurrent	343	265
Accrued Operating Expenses Payroll And Related Expenses Current	130	121
Accrued Liabilities To Client Communities Current	23	27
Interest Payable, Current	17	12
Dividends Payable, Current	1	11
Other Liabilities, Current	34	40
Accrued expenses and other current liabilities	$ 205	$ 211