CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 36,679	$ 23,193
Other comprehensive income (loss), net of tax:
Unrealized holding gain (loss) on securities available for sale arising during the period, net of tax of $4,191 and $5,444	(17,698)	10,110
Unrealized gain on cash flow hedges arising during the period, net of tax of $106 and $11	644	23
Reclassification adjustment for net gains included in net income, net of tax of $302 and $115	(1,137)	(215)
Defined benefit pension plan amortization of prior service cost, net of tax of $32	0	(59)
Total other comprehensive income (loss), net of tax	(18,191)	9,859
Comprehensive income	$ 18,488	$ 33,052