Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 18,424	$ 22,251	$ 34,580	$ 43,172
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 $4,213 and $(333), and for six months of $7,987 and $(2,598), respectively	12,845	(1,017)	24,349	(7,921)
Less: Reclassification adjustment for realized gains (losses) on sale of securities available for sale included in net income, net of income tax expense (benefit) for six months of $(72) and $2, respectively	0	0	220	(7)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(1,261)	0
Total other comprehensive income (loss)	11,584	(1,017)	22,356	(7,928)
Total comprehensive income	$ 30,008	$ 21,234	$ 56,936	$ 35,244