Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net Income	$ 266,400	$ 210,544	$ 181,878
Other Comprehensive Income, Net of Tax
Unrealized gains (losses) on available-for-sale securities	139,208	77,158	(15,608)
Reclassification adjustment for (gains) losses included in net income	(1,138)	(14,423)	12
Net unrealized gains (losses) on available-for-sale securities	138,070	62,735	(15,596)
Tax effect	(34,853)	(15,896)	3,952
Net of tax amount	103,217	46,839	(11,644)
Unrealized (losses) gains on derivatives used for cash flow hedges	(472)	(7,047)	3,286
Reclassification adjustment for losses included in net income	0	10,816	2,334
Net unrealized gains (losses) on derivatives used for cash flow hedges	(472)	3,769	5,620
Tax effect	119	(955)	(1,424)
Net of tax amount	(353)	2,814	4,196
Total other comprehensive income (loss), net of tax	102,864	49,653	(7,448)
Total Comprehensive Income	$ 369,264	$ 260,197	$ 174,430