Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 29,069	$ 22,516	$ 63,649	$ 65,688
Other comprehensive income (loss), net of tax:
Unrealized gains (losses) on investment securities arising during the period, net of income tax expense (benefit) for three months of $2,306 and $(1,328), and for nine months of $10,293 and $(3,926), respectively	7,028	(4,047)	31,377	(11,968)
Reclassification adjustment for realized gains on sale of securities available for sale included in net income, net of income tax expense for three months of $83 and $0, and for nine months of $11 and $2, respectively	(254)	0	(34)	(7)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(669)	0
Reclassification of loss on cash flow hedge arising during the 2019 periods, net of income tax benefit for three months of $10 and for nine months of $12	32	0	(36)	0
Total other comprehensive income (loss)	6,137	(4,047)	28,493	(11,975)
Total comprehensive income	$ 35,206	$ 18,469	$ 92,142	$ 53,713