CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 880,690	$ 578,276	$ 487,476
Other comprehensive income (loss):
Unrealized gains (losses) on investments	7,764	7,993
Unrealized gains (losses) on investments			(2,561)
Unrealized gains (losses) on cash flow hedges	(36,511)	(38,414)
Unrealized gains (losses) on cash flow hedges			11,907
Total unrealized gains (losses)	(28,747)	(30,421)	9,346
Income tax (expense) benefit	6,914	7,431	(2,333)
Other comprehensive income (loss), net of tax (expense) benefit	(21,833)	(22,990)	7,013
Total comprehensive income	$ 858,857	$ 555,286	$ 494,489