Mortgage Banking (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Mortgage servicing assets:
Balance at beginning of period	$ 10,219	$ 10,602	$ 10,436
Loans sold, servicing retained	3,464	1,786	2,808
Servicing assets acquired			0
Amortization of mortgage servicing rights	(3,562)	(2,169)	(2,642)
Carrying value before valuation allowance at end of period	10,121	10,219	10,602
Valuation allowance:
Balance at beginning of period	(1,529)	(1,125)	(1,478)
Impairment recovery (charges)	(759)	(404)	353
Balance at end of period	(2,288)	(1,529)	(1,125)
Net carrying value of MSRs at end of period	7,833	8,690	9,477
Fair value of MSRs at end of period	$ 7,833	$ 8,690	$ 9,477