Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net income	$ 20,162	$ 19,155	$ 63,364	$ 61,625
Other comprehensive income (loss), before tax:
Change in net unrealized gains/losses during period	10,855	(3,773)	12,264	12,942
Reclassification adjustment for net (gains) losses included in income	(23)	8	(75)	(80)
Change in unamortized loss on available-for-sale securities transferred into held-to-maturity	448	451	1,353	902
Unrealized loss on derivatives	(436)	0	(436)	0
Defined benefit post-retirement benefits plans:
Change in net actuarial loss	15	33	43	103
Other comprehensive income (loss), before tax	10,859	(3,281)	13,149	13,867
Deferred tax benefit (expense) related to other comprehensive income	(4,273)	1,291	(5,174)	(5,456)
Other comprehensive income (loss), net of tax	6,586	(1,990)	7,975	8,411
Comprehensive income, net of tax	$ 26,748	$ 17,165	$ 71,339	$ 70,036