Supplemental Comprehensive Income Disclosures Supplemental Comprehensive Income Disclosures (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income [Line Items]
Balance at beginning of period	$ (2,386)	$ (4,499)	$ (20,588)
Other comprehensive loss before reclassification adjustment	(4,409)	2,112	16,657
Amounts reclassified from accumulated other comprehensive income (loss)	(447)	67	(364)
Net gain	215	(66)	(204)
Net other comprehensive loss during the period	(4,641)	2,113	16,089
Balance at end of period	(7,027)	(2,386)	(4,499)
Securities Available for Sale
Accumulated Other Comprehensive Income [Line Items]
Balance at beginning of period	(2,956)	(4,875)	(20,868)
Other comprehensive loss before reclassification adjustment	(4,098)	1,820	16,350
Amounts reclassified from accumulated other comprehensive income (loss)	(401)	99	(357)
Net other comprehensive loss during the period	(4,499)	1,919	15,993
Balance at end of period	(7,455)	(2,956)	(4,875)
Derivatives
Accumulated Other Comprehensive Income [Line Items]
Balance at beginning of period	560	300	0
Other comprehensive loss before reclassification adjustment	(311)	292	307
Amounts reclassified from accumulated other comprehensive income (loss)	(46)	(32)	(7)
Net other comprehensive loss during the period	(357)	260	300
Balance at end of period	203	560	300
Post-Retirement Obligation
Accumulated Other Comprehensive Income [Line Items]
Balance at beginning of period	10	76	280
Net gain	215	(66)	(204)
Net other comprehensive loss during the period	215	(66)	(204)
Balance at end of period	$ 225	$ 10	$ 76