CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 29,082	$ 3,196	$ (152,867)	$ (68,010)
Amounts related to available for sale securities:
Change in net unrealized gain or loss	(12,563)	(2,692)	(13,674)	87,969
Reclassification adjustment for amounts included in net income (loss)			66,864	1,365
Amounts related to cash flow hedges:
Change in net unrealized gain or loss	2,113	(7,648)	(19,705)	(22,945)
Reclassification adjustment for amounts included in net income (loss)	952	(2,702)	2,370	(19,624)
Other comprehensive income	(9,498)	(13,042)	35,855	46,765
Comprehensive income (loss)	$ 19,584	$ (9,846)	$ (117,012)	$ (21,245)