Capital and Operating Leases (Details Textuals) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 percent years	Dec. 31, 2010	Dec. 31, 2009
Schedule of Leased Assets [Line Items]
Operating Leases, Rent Expense	$ 71	$ 54	$ 58
Period For Extension of Renewal Options of Capital Lease Contract	5
Ownership Interest with Lessee	40.00%
Period For Extenstion of Renewal Options of Capital Lease Contract 1	3
Period For Extension of Renewal Options of Capital Lease Contract 2	5