Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Assets:
Investments	$ 70	$ 61
Foreign currency hedges		4
Total Assets	70	65
Liabilities:
Deferred compensation	201	173
Foreign currency hedges	2
Total Liabilities	203	173
Level 1 [Member]
Assets:
Investments	70	61
Foreign currency hedges		0
Total Assets	70	61
Liabilities:
Deferred compensation	0	0
Foreign currency hedges	0
Total Liabilities	0	0
Level 2 [Member]
Assets:
Investments	0	0
Foreign currency hedges		4
Total Assets	0	4
Liabilities:
Deferred compensation	201	173
Foreign currency hedges	2
Total Liabilities	203	173
Level 3 [Member]
Assets:
Investments	0	0
Foreign currency hedges		0
Total Assets	0	0
Liabilities:
Deferred compensation	0	0
Foreign currency hedges	0
Total Liabilities	$ 0	$ 0