CONSOLIDATED CONDENSED 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	$ 41,113	$ 24,358	$ 117,426	$ 71,687
Other comprehensive income (loss), net of tax:
Unrealized holding gain (loss) on securities available for sale arising during the period, net of tax of $2,596, $4,101, $7,470 and $4,374	(9,765)	(7,617)	(30,032)	8,124
Unrealized gain (loss) on cash flow hedges arising during the period, net of tax of $44, $3, $212 and $134	166	(7)	1,039	(246)
Reclassification adjustment for net gains included in net income, net of tax of $250, $32, $766 and $258	(942)	(60)	(2,882)	(480)
Defined benefit pension plan amortization of prior service cost, net of tax of $31 and $94	0	(58)	0	(175)
Total other comprehensive income (loss), net of tax	(10,541)	(7,742)	(31,875)	7,223
Comprehensive income	$ 30,572	$ 16,616	$ 85,551	$ 78,910