Fair Value Measurements (Details Textuals) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Fair Value Measurements (Textuals) [Abstract]
Average pull through percentage used in measuring fair value of interest rate lock commitments			77.00%		78.00%
Fair value assets measured on nonrecurring basis
Total foreclosure-related charges	$ 24	$ 20	$ 39	$ 43