Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member
Cumulative effect change in accounting principle	$ 844,170	$ 939,889	$ 698,725	$ 793,796	$ 866,204	$ 1,018,413
Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect change in accounting principle	$ (3,267,064)	(3,142,089)	(3,393,088)	$ (3,301,680)	(3,223,222)	(3,069,272)
Accumulated Deficit | Cumulative Effect Period Of Adoption Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect change in accounting principle		$ 0	$ (115)		$ 0	$ (55,885)