Unaudited Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 51,610	$ 49,336	$ 153,134	$ 132,279
Other Comprehensive Income (Loss), Net of Tax
Unrealized gains (losses) on available-for-sale securities	11,113	(14,190)	87,442	(46,597)
Reclassification adjustment for (gains) losses included in net income	(13,811)	(151)	(14,166)	195
Net unrealized gains (losses) on available-for-sale securities	(2,698)	(14,341)	73,276	(46,402)
Tax effect	684	3,634	(18,568)	11,759
Net of tax amount	(2,014)	(10,707)	54,708	(34,643)
Unrealized (losses) gains on derivatives used for cash flow hedges	(1,393)	1,234	(7,047)	7,302
Reclassification adjustment for losses included in net income	10,315	469	10,816	1,946
Net unrealized gains on derivatives used for cash flow hedges	8,922	1,703	3,769	9,248
Tax effect	(2,261)	(431)	(955)	(2,343)
Net of tax amount	6,661	1,272	2,814	6,905
Total other comprehensive income (loss), net of tax	4,647	(9,435)	57,522	(27,738)
Total Comprehensive Income	$ 56,257	$ 39,901	$ 210,656	$ 104,541