Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 58,378	$ 49,111
Unrealized gains on securities
Before tax	7,379	25,176
Tax effect	(2,900)	(9,988)
Net of tax	4,479	15,188
Reclassification of net (losses) gains included in net income
Before tax	(55)	1,325
Tax effect	21	(521)
Net of tax	(34)	804
Reclassification of amortization of unrealized gains and losses on investment securities transferred to held-to-maturity from available-for-sale
Before tax	1,428	(3,425)
Tax effect	(561)	1,339
Net of tax	867	(2,086)
Net unrealized gains on securities	3,646	16,470
Unrealized gains on derivative instruments
Before tax	1,615	478
Tax effect	(634)	(188)
Net unrealized gains on derivative instruments	981	290
Foreign currency adjustment
Before tax	1,215	8,347
Tax effect	(338)	(2,309)
Net foreign currency adjustment	877	6,038
Total other comprehensive income	5,504	22,798
Comprehensive income	$ 63,882	$ 71,909