Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 121,027	$ 73,548	$ 72,100
Other comprehensive income (loss)
Net unrealized holding gains (losses) arising during period on investment securities available for sale, net of tax expense (benefit) of ($849), ($169) and ($2,355)	(3,196)	(314)	(4,374)
Reclassification adjustment for gains on investment securities included in earnings, net of tax of $19, $13 and $33	(70)	(24)	(61)
Net unrealized gains (losses) on cash flow hedge during the period, net of tax expense (benefit) of $30, $63 and $13	112
Net unrealized gains (losses) on cash flow hedge during the period, net of tax expense (benefit) of $30, $63 and $13		116	24
Total other comprehensive income (loss)	(3,154)	(222)	(4,411)
Comprehensive income	$ 117,873	$ 73,326	$ 67,689