Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 81,466	$ 89,580	$ 170,612	$ 171,561
Unrealized gains (losses) on available-for-sale securities
Before tax	26,177	(9,455)	64,452	(45,639)
Tax effect	(6,977)	2,541	(17,296)	12,251
Net of tax	19,200	(6,914)	47,156	(33,388)
Reclassification of net gains (losses) on available-for-sale securities included in net income
Before tax	523	(20)	456	(995)
Tax effect	(140)	8	(122)	270
Net of tax	383	(12)	334	(725)
Reclassification of amortization of unrealized gains on investment securities transferred to held-to-maturity from available-for-sale
Before tax	214	20	358	16
Tax effect	(57)	(5)	(98)	(4)
Net of tax	157	15	260	12
Net unrealized gains (losses) on available-for-sale securities	18,660	(6,917)	46,562	(32,675)
Unrealized (losses) gains on derivative instruments
Before tax	(22,168)	1,082	(27,164)	4,157
Tax effect	5,918	(290)	7,263	(1,116)
Net unrealized (losses) gains on derivative instruments	(16,250)	792	(19,901)	3,041
Foreign currency adjustment
Before tax	3,232	(2,660)	6,123	(6,513)
Tax effect	(727)	664	(1,341)	1,620
Net foreign currency adjustment	2,505	(1,996)	4,782	(4,893)
Total other comprehensive income (loss)	4,915	(8,121)	31,443	(34,527)
Comprehensive income	$ 86,381	$ 81,459	$ 202,055	$ 137,034