Mortgage Servicing Rights - At Amortized Cost (Details) (Mortgage loans, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Mortgage loans
Servicing Asset at Amortized Value, Balance [Roll Forward]
Servicing asset at amortized cost, before valuation reserve, beginning	$ 13,224	$ 13,450	$ 13,811
Sales of mortgage servicing rights	0	(735)	0
Originations of mortgage servicing rights	3,581	4,563	2,864
Amorization expense	2,787	3,501	3,225
Write-off of permanent impairment	0	(553)	0
Servicing asset at amortized cost, before valuation reserve, ending	14,018	13,224	13,450
Less valuation reserve	(472)	(571)	(1,895)
Servicing asset at fair value, ending	13,546	12,653	11,555
Principal balance of serviced loans underlying mortgage servicing rights	2,416,621	2,146,351	1,803,303
Mortgage servicing rights as a percentage of serviced loans	0.0056	0.0059	0.0064
Disclosure of Transfer of Securitizations or Asset-backed Financing Financial Assets Accounted for as Sale [Abstract]
Carrying value of sold mortgage servicing rights		735
Losses on sale of mortgage servicing rights recorded as other expense		$ (19)