Mortgage Banking (Details) (USD $)	1 Months Ended	3 Months Ended
	Nov. 30, 2013	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Mortgage Banking [Abstract]
Period of put back response		60 days
Residential mortgage loans sold		$ 184,900,000	$ 392,000,000
Gains on sales of residential mortgage loans, before tax		1,800,000	10,200,000
Mortgage loans serviced for others		5,514,000,000		5,461,000,000
Mortgage servicing rights [Abstract]
Balance at beginning of period		67,834,000	47,341,000
Origination of servicing assets		2,315,000	5,521,000
Change in fair value [Abstract]
Due to market changes		(723,000)	1,127,000
Due to runoff		(1,812,000)	(2,460,000)
Balance at end of period		67,614,000	51,529,000
Mortgage loan servicing representation and warranty expenses		150,000	590,000
Reserve for mortgage loan servicing put back expenses		1,100,000		1,100,000
Payments to FNMA for repurchase obligations	$ 3,600,000