Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net income	$ 24,467	$ 16,767	$ 61,326	$ 46,816
Other comprehensive income (loss), net of tax:
Net unrealized gains (losses) on investment securities available-for-sale, net of tax expense (benefit) of $655 and $(615) for the three months ended September 30, 2015 and 2014, respectively, and $832 and $1,150 for the nine months ended September 30, 2015 and 2014, respectively	1,214	(1,144)	1,545	2,136
Reclassification adjustment for realized gain on sale of investment securities available-for-sale included in net income, net of tax expense of $2 for the three months ended September 30, 2015 and $214 for the nine months ended September 30, 2015	(3)	0	(398)	0
Adjustment for pension and other postretirement benefits, net of tax expense (benefit) of $381 and $(201) for the three months ended September 30, 2015 and 2014, respectively, and $1,142 and $(604) for the nine months ended September 30, 2015 and 2014, respectively	707	(374)	2,120	(1,122)
Total other comprehensive income (loss), net of tax	1,918	(1,518)	3,267	1,014
Comprehensive income	$ 26,385	$ 15,249	$ 64,593	$ 47,830