Litigation and Regulatory Contingencies (Details) (USD $)				3 Months Ended
	Mar. 31, 2012	Mar. 31, 2012 Litigation And Regulatory Action [Member]	Dec. 31, 2011 Litigation And Regulatory Action [Member]	Mar. 31, 2012 Pending or Threatened Litigation [Member] loans	Feb. 06, 2012 Pending or Threatened Litigation [Member]
Loss Contingency Accrual, at Carrying Value	$ 0	$ 3,300,000	$ 6,900,000
Number of Residential Mortgage Loans Involved in Breach of Contract in Appraisal Services				194
Loss Contingency, Damages Sought, Value				129,000,000
Breach Of Contract Claim					$ 16,000,000
Number Of Breach Of Contract Claims Related To Appraisal Services					26