Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net income	$ 15,154	$ 16,738	$ 45,618	$ 51,121
Other comprehensive (loss) income:
(Decrease) increase in net unrealized gains on securities available for sale	(4,884)	(712)	9,305	(18,173)
Deferred tax benefit (expense)	2,054	299	(3,912)	7,641
(Decrease) increase in net unrealized gains on securities available for sale, net of tax	(2,830)	(413)	5,393	(10,532)
Post-retirement benefit transition obligation amortization	15	15	45	45
Deferred tax expense	(6)	(6)	(18)	(18)
Post-retirement benefit transition obligation amortization, net of tax	9	9	27	27
Total other comprehensive (loss) income	(2,821)	(404)	5,420	(10,505)
Total comprehensive income	$ 12,333	$ 16,334	$ 51,038	$ 40,616