Capital and Operating Leases (Details Textuals) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Leased Assets [Line Items]
Operating Leases, Rent Expense	$ 36	$ 40	$ 32
Capital Leases, Contingent Rental Payments Due	$ 27
Period For Extension of Renewal Options of Capital Lease Contract	5 years
Ownership Interest with Lessee	40.00%
Period For Extenstion of Renewal Options of Capital Lease Contract 1	3 years
Period For Extension of Renewal Options of Capital Lease Contract 2	5 years