Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 107,315	$ 99,121	$ 191,786	$ 269,733
Unrealized (losses) gains on available-for-sale securities
Before tax	(14,563)	18,231	81,859	82,683
Tax effect	3,881	(4,860)	(21,816)	(22,156)
Net of tax	(10,682)	13,371	60,043	60,527
Reclassification of net gains on available-for-sale securities included in net income
Before tax	50	400	200	856
Tax effect	(14)	(108)	(54)	(230)
Net of tax	36	292	146	626
Reclassification of amortization of unrealized gains on investment securities transferred to held-to-maturity from available-for-sale
Before tax	54	58	178	416
Tax effect	(14)	(16)	(47)	(114)
Net of tax	40	42	131	302
Net unrealized (losses) gains on available-for-sale securities	(10,758)	13,037	59,766	59,599
Unrealized gains (losses) on derivative instruments
Before tax	10,393	(6,848)	(31,167)	(34,012)
Tax effect	(2,770)	1,834	8,325	9,097
Net unrealized gains (losses) on derivative instruments	7,623	(5,014)	(22,842)	(24,915)
Foreign currency adjustment
Before tax	3,716	(1,889)	(3,939)	4,234
Tax effect	(825)	418	852	(923)
Net foreign currency adjustment	2,891	(1,471)	(3,087)	3,311
Total other comprehensive (loss) income	(244)	6,552	33,837	37,995
Comprehensive income	$ 107,071	$ 105,673	$ 225,623	$ 307,728