Other Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Securities available for sale and transferred securities: Before Tax Amount
Change in net unrealized gain/loss during the period		$ (3,557)	$ 1,580
Reclassification adjustment for net gains included in net income	[1]	0	0
Total other comprehensive income (loss)		(3,557)	1,580
Securities available for sale and transferred securities: Tax Expense (Benefit)
Change in net unrealized gain/loss during the period		747	(553)
Reclassification adjustment for net gains included in net income		0	0
Total other comprehensive income (loss)		747	(553)
Securities available for sale and transferred securities: Net of Tax Amount
Change in net unrealized gain/loss during the period		(2,810)	1,027
Securities Available For Sale, Amounts reclassified from accumulated other comprehensive income		0	0
Other comprehensive income (loss)		$ (2,810)	$ 1,027

[1] Amounts are included in gains on sale or call of securities on the consolidated condensed statements of income. Income tax expense associated with the reclassification adjustments, included in federal income taxes, for the three months ended March 31, 2018 and 2017 was $0 and $0, respectively.