Mortgage Servicing Rights Summary of Changes in Mortgage Servicing Rights (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Valuation Allowance:
Valuation Allowance for Impairment of Recognized Servicing Assets, Period Increase (Decrease)			$ 0
Residential Mortgage [Member]
Amortized Cost:
Balance at beginning of period	32,809	25,327	30,700	23,498
Originations of mortgage servicing rights	2,213	3,197	6,881	6,870
Amortization expense	(1,343)	(998)	(3,902)	(2,842)
Balance at end of period	33,679	27,526	33,679	27,526
Valuation Allowance:
Balance at beginning of period	(1,550)	(1,000)	(1,550)	(1,000)
Additions	0	(550)	0	(550)
Balance at end of period	(1,550)	(1,550)	(1,550)	(1,550)
Net MSRs at end of period	$ 32,129	$ 25,976	$ 32,129	$ 25,976