Comprehensive Income - Components of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated other comprehensive income (loss)
Beginning balance	$ (2,332)	$ (2,237)	$ (2,642)	$ (2,961)
Other comprehensive loss before reclassification	(19)	(8)	290	748
Amounts reclassified from AOCI	36	(143)	37	(175)
Net current period OCI	17	(151)	327	573
Ending balance	(2,315)	(2,388)	(2,315)	(2,388)
Available-for-sale securities, Unrealized holding gains
Accumulated other comprehensive income (loss)
Beginning balance	(412)	(563)	(406)	(1,476)
Other comprehensive loss before reclassification	259	126	329	1,113
Amounts reclassified from AOCI	(2)	(163)	(78)	(237)
Net current period OCI	257	(37)	251	876
Ending balance	(155)	(600)	(155)	(600)
Defined benefit pension plan items, Change in defined benefit pension plan
Accumulated other comprehensive income (loss)
Beginning balance	(1,920)	(1,674)	(2,236)	(1,485)
Other comprehensive loss before reclassification	(278)	(134)	(39)	(365)
Amounts reclassified from AOCI	38	20	115	62
Net current period OCI	(240)	(114)	76	(303)
Ending balance	$ (2,160)	$ (1,788)	$ (2,160)	$ (1,788)