Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net income	$ 7,892	$ 9,766	$ 19,633	$ 18,575
Available-for-sale investment securities:
Gross unrealized holding (loss) gain arising in the period	(2,661)	2,272	(12,774)	5,684
Related tax benefit (expense)	559	(795)	2,683	(1,989)
Less: reclassification adjustment for net (loss) gain included in net income	(147)	18	(146)	358
Related tax benefit (expense)	31	(6)	31	(125)
Amounts reclassified out of accumulated other comprehensive loss per ASU 2016-01 (a)	0	0	(5,020)	0
Related tax benefit	0	0	1,054	0
Net effect on other comprehensive (loss) income	(1,986)	1,465	(13,942)	3,462
Defined benefit plans:
Net loss arising during the period	0	(1)	0	0
Amortization of unrecognized loss and service cost on benefit plans	26	24	52	47
Related tax expense	(5)	(8)	(11)	(16)
Net effect on other comprehensive income	21	15	41	31
Cash flow hedges:
Net gain (loss) arising during the period	537	(666)	1,915	(769)
Related tax (expense) benefit	(113)	233	(402)	269
Net effect on other comprehensive income (loss)	424	(433)	1,513	(500)
Total other comprehensive (loss) income, net of tax expense	(1,541)	1,047	(12,388)	2,993
Total comprehensive income	$ 6,351	$ 10,813	$ 7,245	$ 21,568