CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income		$ 8,895	$ 6,710
Unrealized gains (losses) on securities:
Unrealized holding gain (loss) arising during period		6,167	(7,592)
Less: reclassification adjustment for gains included in net income	[1]	(6)
Other comprehensive income (loss), before tax		6,161	(7,592)
Income tax expense related to items of other comprehensive income (loss), net of tax		(1,821)	2,245
Other comprehensive income (loss)		4,340	(5,347)
Comprehensive income		$ 13,235	$ 1,363

[1] Amounts are included in net gains on investment securities available-for-sale on the Consolidated Statements of Income in non-interest revenue. Income tax expense associated with the reclassification adjustment for the three months ended March 31, 2019 and 2018 was $2 thousand and $0 thousand respectively.