Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net income	$ 21,868	$ 25,554	$ 44,994	$ 45,678
Other comprehensive income (loss), before tax:
Change in net unrealized gains/losses during period	8,006	10,043	17,365	18,671
Reclassification adjustment for net (gains) losses included in income	(5)	(108)	(7)	(87)
Change in unamortized loss on available-for-sale securities transferred into held-to-maturity	464	452	929	904
Unrealized loss on derivatives	(486)	(804)	(437)	(3,002)
Defined benefit post-retirement benefits plans:
Change in net actuarial loss	(176)	13	(914)	28
Other comprehensive income (loss), before tax	7,803	9,596	16,936	16,514
Deferred tax benefit (expense) related to other comprehensive income	(3,214)	(3,775)	(6,812)	(6,498)
Other comprehensive income (loss), net of tax	4,589	5,821	10,124	10,016
Comprehensive income, net of tax	$ 26,457	$ 31,375	$ 55,118	$ 55,694