Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Net income	$ 20,124	$ 20,980
Other comprehensive income (loss), before tax:
Change in net unrealized gains/losses during period	8,613	10,608
Reclassification adjustment for net (gains) losses included in income	21	(6)
Change in unamortized loss on available-for-sale securities transferred into held-to-maturity	465	451
Unrealized loss on derivatives	(2,197)	0
Defined benefit post-retirement benefits plans:
Change in net actuarial loss	15	15
Other comprehensive income (loss), before tax	6,917	11,068
Deferred tax benefit (expense) related to other comprehensive income	(2,722)	(4,355)
Other comprehensive income (loss), net of tax	4,195	6,713
Comprehensive income, net of tax	$ 24,319	$ 27,693