Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income		$ 393,968	$ 182,871	$ 81,520
Other comprehensive income/(loss), net of tax:
Changes in unrealized gains/(losses) on available-for-sale securities, net of tax	[1],[2],[3]	(36,254)	4,730	5,803
Changes in unrealized gains/(losses) on cash flow hedging instruments, net of tax	[2],[3],[4]	(792)	(320)	7,288
Foreign currency translation adjustment, net of tax	[2],[3]	(5,691)	7,896	(12,600)
Total other comprehensive income/(loss), net of tax		(42,737)	12,306	491
Comprehensive income		$ 351,231	$ 195,177	$ 82,011

[1] Amounts are net of reclassifications to earnings of realized losses of $2.9 and realized gains of $0.2 million for the years ended December 31, 2018 and 2017, respectively. There were no reclassifications to earnings of realized gains for the year ended December 31, 2016.

[2] Net of a tax benefit of $11.2 million and tax expenses of $3.3 million and $0.3 million for the years ended December 31, 2018, 2017, and 2016, respectively.

[3] The adoption of ASU 2018-02 on January 1, 2018 resulted in a reclassification of $3.1 million to retained earnings related to cash flow hedges and investment portfolio risk. The reclassification is reflected in the activity for the year ended December 31, 2018. See Note 2 for further details.

[4] Amounts are net of reclassifications to earnings of gains of $4.9 million and losses of $0.6 million and $5.4 million for the years ended December 31, 2018, 2017, and 2016, respectively.