Consolidated Condensed Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net Income	$ 25,455	$ 31,123
Other comprehensive income, net of tax:
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	0	2,024
Unrealized net holding gain (loss) on debt securities available-for-sale, net of income tax effect of $3,866 and $(6,223) for the three months ended March 31, 2019 and 2018, respectively	14,541	(23,410)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	(206)	0
Other comprehensive income (loss)	14,335	(21,386)
Comprehensive income	39,790	9,737
Accounting Standards Update 2016-01 [Member]
Other comprehensive income, net of tax:
Other comprehensive income (loss)	14,335
Accumulated Other Comprehensive Income (loss) [Member]
Other comprehensive income, net of tax:
Unrealized net holding gain (loss) on debt securities available-for-sale, net of income tax effect of $3,866 and $(6,223) for the three months ended March 31, 2019 and 2018, respectively	$ 14,335	$ (21,386)