Other Comprehensive Income (Loss) - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of securities, net	$ (338)	$ 0	$ (347)	$ (20)
Tax expense	574	993	(2,058)	2,986
Interest expense	1,566	1,414	4,543	4,231
Net earnings (loss)	1,666	2,398	(1,257)	7,240
Unrealized gains and losses on securities available-for-sale: | Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax expense	119	0	121	7
Net earnings (loss)	219	0	226	13
Unrealized gains and losses on securities available-for-sale: | Interest Rate Contract | Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of securities, net	(338)	0	(347)	(20)
Gains on derivative instruments: | Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax expense	1	0	1	0
Net earnings (loss)	(3)	0	(3)	0
Gains on derivative instruments: | Interest Rate Contract | Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ (4)	$ 0	$ (4)	$ 0