CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net Income		$ 12,820	$ 10,076
Net change in unrealized gains (losses) on available-for-sale securities:
Net change in unrealized losses on available-for-sale securities, net of tax of $2,666 and $247, respectively		(9,729)	(458)
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 ($355) and ($48) respectively		1,328	90
Net reclassification adjustment for effective portion of cash flow hedges, net of tax of ($13) and ($159), respectively(1)	[1]	51	296
Net change in unrealized losses on cash flow hedging derivatives, net of tax		1,379	386
Reclassification of amortization of net unrecognized actuarial loss and prior service cost, net of tax of ($31) and ($23), respectively(2)	[2]	116	43
Other comprehensive loss		(8,234)	(29)
Comprehensive Income		$ 4,586	$ 10,047

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

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