Litigation and Regulatory Contingencies (Details) (USD $)				0 Months Ended	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2013 Litigation And Regulatory Action [Member]	Dec. 31, 2012 Litigation And Regulatory Action [Member]	Dec. 04, 2012 Pending or Threatened Litigation [Member] loans	Mar. 31, 2012 Pending or Threatened Litigation [Member]	Apr. 25, 2012 Pending or Threatened Litigation [Member]	Feb. 06, 2012 Pending or Threatened Litigation [Member] Claims	Nov. 01, 2011 Pending or Threatened Litigation [Member] loans
Loss Contingency Accrual, at Carrying Value	$ 0	$ 1,900,000	$ 2,400,000
Number of Residential Mortgage Loans Involved in Breach of Contract in Appraisal Services				160				194
Loss Contingency, Damages Sought, Value				108,000,000	129,000,000
Breach Of Contract Claim						$ 16,000,000
Number Of Breach Of Contract Claims Related To Appraisal Services							26