Commitments and Contingencies - (Reserve for Loan Repurchases) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Reserve For Loan Respurchases [Roll Forward]
Beginning balance	$ 2,394	$ 2,401	$ 2,269	$ 3,658
Provision	522	124	1,103	2,752
Loss on repurchased loans and settlements	(312)	(254)	(768)	(4,139)
Ending balance	$ 2,604	$ 2,271	$ 2,604	$ 2,271