Mortgage Servicing Rights - Summary of MSR Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Servicing Asset at Amortized Cost, Balance
Carrying amount before valuation allowance at beginning of year	$ 13,181	$ 14,136	$ 15,595
Additions – servicing obligations that result from transfers of financial assets	1,301	1,352	1,123
Amortization	(2,160)	(2,307)	(2,582)
Carrying amount before valuation allowance at end of year	12,322	13,181	14,136
Valuation Allowance for Impairment of Recognized Servicing Assets
Valuation allowance at beginning of year	(2,167)	(2,735)	(2,795)
(Provision for) recovery of valuation allowance	(25)	568	60
Valuation allowance at end of year	(2,192)	(2,167)	(2,735)
Net carrying amount at end of year	$ 10,130	$ 11,014	$ 11,401