Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Amounts Reclassified from AOCI [Abstract]
Securities gains	$ 356	$ (288)
Tax expense	3,941	2,460
Net income	14,939	15,814
Unrealized Gains on AFS Securities [Member] | Reclassification Out of Accumulated Other Comprehensive Income [Member]
Amounts Reclassified from AOCI [Abstract]
Securities gains	1	149
Tax expense	0	31
Net income	$ 1	$ 118