Stockholders' Equity and Earnings per Share, Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 96,388	$ 93,990
Ending Balance	94,998	95,121
Other comprehensive income, pretax [Abstract]
Unrealized holding gains (losses) arising during the period, pretax	(2,217)	648
Reclassification adjustment for gains recognized in income, pretax	(80)	0
Total change in accumulated other comprehensive loss, net, pretax	(2,297)	648
Other Comprehensive Income, Tax Effect [Abstract]
Unrealized holding gains (losses) arising during the period, tax effect	(466)	220
Reclassification adjustment for gains recognized in income, tax effect	(17)	0
Total change in accumulated other comprehensive loss, net, tax effect	(483)	220
Other Comprehensive Income, Net of Tax [Abstract]
Unrealized holding gains (losses) arising during the period, net of tax	(1,751)	428
Reclassification adjustment for gains recognized in income, net of tax	(63)	0
Other comprehensive income (loss), net of tax	(1,814)	428
ASU 2018-02 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification of the income tax effects of the Tax Cuts and Jobs Act from AOCI			$ 0
ASU 2016-01 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption			0
Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(707)	(1,739)
Net other comprehensive income (loss)	(1,814)	428
Ending Balance	(2,737)	(1,311)
Unrealized Gains (Losses) on Available-for-Sale Securities [Member] | ASU 2018-02 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification of the income tax effects of the Tax Cuts and Jobs Act from AOCI			(139)
Unrealized Gains (Losses) on Available-for-Sale Securities [Member] | ASU 2016-01 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption			(77)
Defined Benefit Pension Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	0	(2,469)
Net other comprehensive income (loss)	0	0
Ending Balance	0	(2,469)
Defined Benefit Pension Plans [Member] | ASU 2018-02 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification of the income tax effects of the Tax Cuts and Jobs Act from AOCI			0
Defined Benefit Pension Plans [Member] | ASU 2016-01 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption			0
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(707)	(4,208)
Net other comprehensive income (loss)	(1,814)	428
Ending Balance	(2,737)	(3,780)
Other Comprehensive Income, Net of Tax [Abstract]
Other comprehensive income (loss), net of tax	$ (1,814)	$ 428
Accumulated Other Comprehensive Loss [Member] | ASU 2018-02 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification of the income tax effects of the Tax Cuts and Jobs Act from AOCI			(139)
Accumulated Other Comprehensive Loss [Member] | ASU 2016-01 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption			$ (77)