Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 11,401	$ 12,170	$ 22,922	$ 21,458
Other comprehensive income (loss), net of tax:
Securities available for sale and transferred securities	5,239	(2,487)	10,742	(8,757)
Hedging derivative instruments	(106)	227	(360)	123
Pension and post-retirement obligations	261	127	522	254
Total other comprehensive income (loss), net of tax	5,394	(2,133)	10,904	(8,380)
Comprehensive income	$ 16,795	$ 10,037	$ 33,826	$ 13,078

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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