CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net Income		$ 14,057	$ 11,339	$ 39,094	$ 31,649
Net change in unrealized losses on available-for-sale securities:
Net change in unrealized losses on available-for-sale securities, net of tax of $887, $142, $4,376 and ($784), respectively		(3,240)	(262)	(15,963)	1,458
Net reclassification adjustment for net losses (gains) included in net income, net of tax of ($59), $289, ($66) and $289, respectively(1)	[1]	216	(538)	240	(538)
Net change in unrealized losses on available-for-sale securities, net of tax		(3,024)	(800)	(15,723)	920
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Net change in unrealized losses on cash flow hedging derivatives, net of tax of ($127), $43, ($556) and $243, respectively		462	(80)	2,031	(452)
Net reclassification adjustment for effective portion of cash flow hedges, net of tax of ($38), ($128), ($143) and ($432), respectively(2)	[2]	139	238	522	802
Net change in unrealized losses on cash flow hedging derivatives, net of tax		601	158	2,553	350
Reclassification of amortization of net unrecognized actuarial loss and prior service cost, net of tax of ($31), ($23), ($94) and ($69), respectively(3)	[3]	115	42	347	128
Other comprehensive (loss) income		(2,308)	(600)	(12,823)	1,398
Comprehensive Income		$ 11,749	$ 10,739	$ 26,271	$ 33,047

[1] (1)Reclassified into the consolidated statements of income within net gain on sale of securities.

[2] (2) Reclassified into the consolidated statements of income within interest on borrowings and subordinated debentures.

[3] (3) Reclassified into the consolidated statements of income within salaries and employee benefits and other expenses.