Derivative Financial Instruments (Details 4) (Derivative used in Mortgage Banking Activities [Member], USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010
Derivative assets:
Total derivative assets	$ 9,097	$ 23,486	$ 12,725
Derivative liabilities:
Total derivative liabilities	(11,967)	(2,328)	(6,983)
Net derivative liability	(2,870)	21,158	5,742
Interest rate lock agreements [Member]
Derivative assets:
Total derivative assets	8,963	2,817	11,745
Derivative liabilities:
Total derivative liabilities	(124)	(1,445)	(379)
Forward trades and options [Member]
Derivative assets:
Total derivative assets	134	20,669	980
Derivative liabilities:
Total derivative liabilities	$ (11,843)	$ (883)	$ (6,604)