Mortgage Banking Activities, Loans Sold With Recourse (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Residential Mortgage Loans Sold With Recourse [Abstract]
Carrying amount of residential mortgage loans sold and subject to recourse	$ 220,000,000	$ 248,000,000	$ 227,000,000
Percentage of loans sold with recourse and either more than 90 days past due or in bankruptcy or foreclosure (in hundredths)	5.00%
Principal balance of loans sold with recourse and either 90 days or more past due or in bankruptcy or foreclosure	11,000,000
Percentage of loans sold with recourse and 30 to 89 days past due (in hundredths)	5.00%
Principal balance of loans sold with recourse and 30 to 89 days past due	11,000,000
Activity in the allowance for losses on loans sold with recourse [Roll forward]
Beginning balance	11,359,000	18,683,000
Provision for recourse losses	(761,000)	1,672,000
Loans charged off, net	(523,000)	(1,704,000)
Ending balance	10,075,000	18,651,000
Residenital Mortgage Loans Subject to Repurchase Under Standard Representations and Warranties [Abstract]
Number of mortgages purchased under repurchase agreement with government sponsored entities.	9
Purchase price of loans purchased under repurchase agreement with government sponsored entities	1,000,000
Losses incurred on actual repurchased loans from governmental sponsored entities with warranties	158,000
Number of loans sold under standard representations and warranties indemnified	5
Losses on mortgage loan indemnified during period	409,000
Number of loans with unresolved deficiency requests	430		389
Principal balance of loans with unresolved deficiency requests	50,861,000		44,831,000
Unpaid principal balance of mortgage loans subject to indemnification under standard representations and warranties	1,414,000		1,233,000
Accrual for credit losses for loan repurchase under representations and warranties	$ 5,877,000		$ 5,291,000