Mortgage Servicing Rights Summary of Changes in Mortgage Servicing Rights (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Amortization [Abstract]
2013	$ 2,138
2014	1,259
2015	247
Mortgage [Member]
Amortized Cost:
Balance at beginning of period	34,666	30,700
Originations of mortgage servicing rights	15,451	9,884
Amortization expense	(10,380)	(5,918)
Balance at end of period	39,737	34,666
Valuation Allowance:
Balance at beginning of period	(1,550)	(1,550)
Additions	(2,130)	0
Balance at end of period	(3,680)	(1,550)
Net MSRs at end of period	36,057	33,116
Valuation Allowance for Impairment of Recognized Servicing Assets, Period Increase (Decrease)	0
Amortization [Abstract]
2013	8,518
2014	7,694
2015	6,782
2016	5,777
2017	$ 4,673