Summary of Significant Accounting Policies (AOCI) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income (loss), net of tax	$ (2,304)	$ (5,761)
Realized gains on available-for-sale securities	616	1,192	$ 452
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Tax	(216)	(465)	(176)
Total reclassifications out of accumulated other comprehensive income	400	727	$ 276
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net unrealized losses on securities available-for-sale	(2,619)	(7,649)
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	281	393
Securities with other-than-temporary impairment losses	(345)	(1,398)
Tax benefit	841	3,134
Other Than Temporary Impairment Losses Investments Portion In Accumulated Other Comprehensive Income Loss Tax Including Portion Attributable To Noncontrolling Interest Available For Sale Securities	(100)	(545)
Other Comprehensive Income (Loss), Tax	941	3,679
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	(2,059)	(4,908)
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Debt Securities	$ 245	$ 853