Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 37,446	$ 31,964	$ 129,181	$ 102,500
Securities available for sale:
Unrealized holding (losses) gains on securities	(62)	(4,882)	20,648	(15,791)
Reclassification adjustment for losses realized in net income	1,876	11	1,872	11
Total securities	1,814	(4,871)	22,520	(15,780)
Derivative instruments:
Unrealized holding (losses) gains on derivative instruments	(708)	639	(3,164)	1,884
Total derivative instruments	(708)	639	(3,164)	1,884
Defined benefit pension and post-retirement benefit plans:
Amortization of net actuarial loss recognized in net periodic pension cost	78	61	234	184
Total defined benefit pension and post-retirement benefit plans	78	61	234	184
Other comprehensive income (loss), net of tax	1,184	(4,171)	19,590	(13,712)
Comprehensive income	$ 38,630	$ 27,793	$ 148,771	$ 88,788

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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