Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Consolidated Statements of Comprehensive Income
Net income	$ 22,300	$ 15,665	$ 53,849	$ 29,517
Net unrealized gain (loss) on securities available-for-sale:
Net unrealized holding gain (loss) on securities arising during the period	4,699	(6,733)	7,692	(6,603)
Reclassification adjustment for gain on sales of securities included in net income		(1,332)		(1,332)
Net unrealized gain (loss) on securities available-for-sale	4,699	(8,065)	7,692	(7,935)
Reclassification adjustment for net actuarial loss on pension plans and other postretirement benefits included in net income	161	542	296	1,169
Reclassification adjustment for prior service cost on pension plans and other postretirement benefits included in net income	31	35	61	69
Total other comprehensive income (loss), net of tax	4,891	(7,488)	8,049	(6,697)
Comprehensive income	$ 27,191	$ 8,177	$ 61,898	$ 22,820