Accrued Expenses and Other Current Liabilities (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Summary of Accrued expenses and other current liabilities
Accrued commissions and incentives	$ 211	$ 213
Accrued payroll and related	71	54
Accrued interest expense	61	59
Customer prepayments	56	16
Accrued sponsor monitoring fees	32	37
Deferred revenue	29	16
Income tax payable	24	19
Derivative contracts	4	37
Pension and post-retirement benefit liabilities	2	2
Other	47	48
Accrued expenses and other current liabilities	$ 537	$ 501