Comprehensive Income - Components of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accumulated other comprehensive income (loss), net of tax
Beginning balance	$ (2,126)	$ (2,554)	$ (2,933)	$ (2,642)
Other comprehensive income (loss) before reclassification, net of tax	866	186	1,866	308
Amounts reclassified from AOCI, net of tax	(98)	36	(291)	2
Net current period OCI	768	222	1,575	310
Ending balance	(1,358)	(2,332)	(1,358)	(2,332)
Available-for-sale securities, Unrealized holding gains
Accumulated other comprehensive income (loss), net of tax
Beginning balance	754	(154)	(363)	(406)
Other comprehensive income (loss) before reclassification, net of tax	1,081	(255)	2,427	70
Amounts reclassified from AOCI, net of tax	(133)	(3)	(362)	(76)
Net current period OCI	948	(258)	2,065	(6)
Ending balance	1,702	(412)	1,702	(412)
Defined benefit pension plan items, Change in defined benefit pension plan
Accumulated other comprehensive income (loss), net of tax
Beginning balance	(2,880)	(2,400)	(2,570)	(2,236)
Other comprehensive income (loss) before reclassification, net of tax	(215)	441	(561)	238
Amounts reclassified from AOCI, net of tax	35	39	71	78
Net current period OCI	(180)	480	(490)	316
Ending balance	$ (3,060)	$ (1,920)	$ (3,060)	$ (1,920)