Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 62,812	$ 89,146
Unrealized gains on available-for-sale securities
Before tax	91,354	38,275
Tax effect	(24,347)	(10,319)
Net of tax	67,007	27,956
Reclassification of net gains (losses) on available-for-sale securities included in net income
Before tax	491	(67)
Tax effect	(132)	18
Net of tax	359	(49)
Reclassification of amortization of unrealized gains on investment securities transferred to held-to-maturity from available-for-sale
Before tax	78	144
Tax effect	(21)	(41)
Net of tax	57	103
Net unrealized gains on available-for-sale securities	66,591	27,902
Unrealized losses on derivative instruments
Before tax	(38,693)	(4,996)
Tax effect	10,322	1,345
Net unrealized losses on derivative instruments	(28,371)	(3,651)
Foreign currency adjustment
Before tax	(14,333)	2,891
Tax effect	3,188	(614)
Net foreign currency adjustment	(11,145)	2,277
Total other comprehensive income	27,075	26,528
Comprehensive income	$ 89,887	$ 115,674