Fair Values (Details 1) (USD $)	Jun. 30, 2012	Dec. 31, 2011
Liabilities [Abstract]
Derivatives	$ 98,000,000	$ 108,000,000
Total liabilities	98,000,000	108,000,000
Level 1 [Member]
Liabilities [Abstract]
Derivatives	0	0
Total liabilities	0	0
Level 2 [Member]
Liabilities [Abstract]
Derivatives	98,000,000	108,000,000
Total liabilities	98,000,000	108,000,000
Level 3 [Member]
Liabilities [Abstract]
Total liabilities	$ 0	$ 0