Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net income	$ 25,707	$ 19,024	$ 48,969	$ 36,859
Other comprehensive income (loss), net of tax:
Net unrealized gains (losses) on investment securities available-for-sale, net of tax expense (benefit) of $742 and $(1,084) for the three months ended June 30, 2016 and 2015, respectively, and $2,212 and $177 for the six months ended June 30, 2016 and 2015, respectively	1,379	(2,014)	4,108	331
Reclassification adjustment for realized gain on sale of investment securities available-for-sale included in net income, net of tax expense of $6 and $10 for the three months ended June 30, 2016 and 2015, respectively, and $13 and $212 for the six months ended June 30, 2016 and 2015, respectively	(12)	(18)	(24)	(395)
Adjustment for pension and other postretirement benefits, net of tax expense (benefit) of $(202) and $380 for the three months ended June 30, 2016 and 2015, respectively, and $(404) and $761 for the six months ended June 30, 2016 and 2015, respectively	(375)	707	(750)	1,413
Total other comprehensive income (loss), net of tax	992	(1,325)	3,334	1,349
Comprehensive income	$ 26,699	$ 17,699	$ 52,303	$ 38,208