Intangible Assets (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Changes in mortgage servicing rights
Balance at beginning of period		$ 2,584
Changes in fair value:
Balance at end of period		2,877
Mortgage servicing rights (MSRs)
Changes in mortgage servicing rights
Balance at beginning of period		2,584	$ 2,847
Originated mortgage servicing rights		49	53
Changes in fair value:
Due to change in model inputs and assumptions	[1]	375	(3)
Other changes in fair value	[2]	(131)	(152)
Balance at end of period		$ 2,877	$ 2,745

[1] The change in fair value resulting from changes in valuation inputs or assumptions used in the valuation model reflects the change in discount rates and prepayment speed assumptions primarily due to changes in interest rates.

[2] Other changes in fair value reflect changes due to customer payments and passage of time.