Fair Values of Financial and Nonfinancial Instruments (Details 2) (Mortgage interest rate lock commitments ("IRLCs"), USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Mortgage interest rate lock commitments ("IRLCs")
Fair value assets reconciliation of changes
Fair value at the beginning of the period			$ 1,496,000	$ 2,055,000
Additions			8,448,000	10,995,000
Gains realized on the conversion of IRLCs to loans	(3,800,000)	(6,200,000)	(6,453,000)	(10,687,000)
Change in valuation of items held			(224,000)	709,000
Fair value at the end of the period	3,267,000	3,072,000	3,267,000	3,072,000
Offsetting gains or losses from instruments used to hedge IRLCs	$ 2,000,000	$ 3,700,000	$ 2,200,000	$ 4,900,000