Other Comprehensive (Loss) Income - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of securities, net	$ 0	$ (6)
Tax expense	(34)	589
Interest expense	1,627	1,465
Net earnings	360	2,491
Unrealized gains and losses on securities available-for-sale: | Reclassifications Out of Accumulated Other Comprehensive (Loss) Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax expense	0	2
Net earnings	0	4
Unrealized gains and losses on securities available-for-sale: | Interest Rate Contract | Reclassifications Out of Accumulated Other Comprehensive (Loss) Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of securities, net	0	(6)
Gains on derivative instruments: | Reclassifications Out of Accumulated Other Comprehensive (Loss) Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax expense	8	0
Net earnings	(32)	0
Gains on derivative instruments: | Interest Rate Contract | Reclassifications Out of Accumulated Other Comprehensive (Loss) Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ (40)	$ 0