Comprehensive Income Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	$ (338)	$ 0	$ 0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(80)	8	7
Other Comprehensive Income (Loss), before Tax	(6,657)	(370)	2,071
Other Comprehensive Income (Loss), Tax	1,692	335	(933)
Other Comprehensive Income	(4,965)	(35)	1,138
Accumulated Net Unrealized Investment Gain (Loss)
Schedule of Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(2,839)	(1,505)	(1,672)
Other Comprehensive Income (Loss), Available-for-sale Securities, before Reclassification Adjustments, Tax	723	565	648
Reclassification from AOCI, Current Period, Tax		(111)	(9)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(2,116)	(940)	(1,024)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax		448	22
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(331)	337	13
Other Comprehensive Income	(2,116)	(603)	(1,011)
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss)
Schedule of Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(3,798)	287	3,017
Reclassification from AOCI, Current Period, Tax	(83)	(49)	(281)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(2,833)	214	1,721
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	325	411	716
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	242	362	435
Other Comprehensive Income (Loss) before Reclassifications, Tax	965	(73)	(1,296)
Other Comprehensive Income	(2,591)	576	2,156
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Cost (Credit)
Schedule of Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(453)
Reclassification from AOCI, Current Period, Tax	(28)	3	5
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(338)	0	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	108	(11)	(12)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	80	(8)	(7)
Other Comprehensive Income (Loss) before Reclassifications, Tax	115
Other Comprehensive Income	$ (258)	$ (8)	$ (7)