Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Net income	$ 13,813	$ 13,234
Other comprehensive income, net of tax:
Net unrealized gains on investment securities available-for-sale, net of tax expense of $857 and $227 for the three months ended March 31, 2014 and 2013, respectively	1,593	420
Reclassification adjustment for realized gain on sale of investment securities available-for-sale included in net income, net of tax expense of $296 for the three months ended March 31, 2013	0	(551)
Adjustment for pension and other postretirement benefits, net of tax expense (benefit) of $(201) and $332 for the three months ended March 31, 2014 and 2013, respectively	(374)	616
Total other comprehensive income, net of tax	1,219	485
Comprehensive income	$ 15,032	$ 13,719