Income Taxes - Components of Income Tax (Details) - USD ($) $ in Thousands	3 Months Ended							6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Components of loss before income taxes and income tax benefit
Loss before income taxes	$ (71,861)	$ (26,772)	$ (37,432)	$ (18,036)	$ (17,822)	$ (17,338)	$ (30,547)	$ (64,204)	$ (47,885)	$ (136,065)	$ (65,707)	$ (627,000)	$ (83,743)	$ (94,903)
Income tax benefit	6,644	17,371						17,371		24,015		30,845		9,295
Net loss attributable to the Company	(65,217)	(9,401)	$ (37,432)	$ (18,036)	$ (17,822)	$ (17,338)	$ (30,547)	(46,833)	$ (47,885)	(112,050)	$ (65,707)	(596,155)	(83,743)	(85,608)
Significant components of deferred income tax expense (benefit)
Deferred tax (benefit) expense												(31,475)	(11,047)	(10,812)
Net operating loss carryforward generated												(52,287)	(5,369)	(10,986)
Valuation allowance increase (decrease)												52,917	16,416	12,503
Benefit for income taxes	$ (6,644)	$ (17,371)						$ (17,371)		$ (24,015)		(30,845)		(9,295)
U.S.
Components of loss before income taxes and income tax benefit
Loss before income taxes												(624,302)	(82,188)	(93,497)
Income tax benefit												30,845		9,295
Net loss attributable to the Company												(593,457)	(82,188)	(84,201)
Significant components of deferred income tax expense (benefit)
Deferred tax (benefit) expense												(31,408)	(10,621)	(11,745)
Net operating loss carryforward generated												(51,849)	(5,099)	(10,321)
Valuation allowance increase (decrease)												52,412	15,720	12,771
Benefit for income taxes												(30,845)		(9,295)
Foreign
Components of loss before income taxes and income tax benefit
Loss before income taxes												(2,698)	(1,555)	(1,407)
Net loss attributable to the Company												(2,698)	(1,555)	(1,407)
Significant components of deferred income tax expense (benefit)
Deferred tax (benefit) expense												(67)	(426)	933
Net operating loss carryforward generated												(438)	(270)	(665)
Valuation allowance increase (decrease)												$ 505	$ 696	$ (268)