Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Net income	$ 20,980	$ 21,393
Other comprehensive income (loss), before tax:
Change in net unrealized gains/losses during period	10,608	14,351
Reclassification adjustment for net (gains) losses included in income	(6)	(71)
Change in unamortized loss on available-for-sale securities transferred into held-to-maturity	451	0
Defined benefit post-retirement benefits plans:
Change in net actuarial loss	15	35
Other comprehensive income (loss), before tax	11,068	14,315
Deferred tax benefit (expense) related to other comprehensive income	(4,355)	(5,633)
Other comprehensive income (loss), net of tax	6,713	8,682
Comprehensive income, net of tax	$ 27,693	$ 30,075