Summary of Significant Accounting Policies (Details) $ in Thousands	Sep. 30, 2021 USD ($)	Sep. 30, 2021 ft²	Sep. 30, 2021	Sep. 30, 2021 Rate	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jan. 01, 2021 USD ($)	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	May 04, 2020 Rate	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Square feet owned | ft²		43,560
Assets held for sale	$ 10,050							$ 0
Deferred income tax liabilities, net	(57,706)							(5,415)
Deferred tax assets, valuation allowance	18,000
Convertible senior notes, net	531,779							168,120
Accumulated deficit	(1,137,245)				$ (1,148,358)	$ (843,714)		(694,294)	$ (666,363)	$ (654,229)		$ (505,043)	$ (507,408)
Foreign Tax Authority
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred tax assets, valuation allowance	3,800							2,600
Additional Paid-in Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit	(1,110,590)				(1,101,298)	(872,350)		(701,357)	(688,832)	(679,235)		(525,929)	(520,278)
Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit	$ (26,922)				$ (47,270)	$ 28,603		7,185	$ 22,602	$ 25,159		$ 18,335	$ 11,357
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred income tax liabilities, net							$ 6,600
Deferred tax assets, valuation allowance							2,000
Convertible senior notes, net							27,200
Accumulated deficit								22,575
Cumulative Effect, Period of Adoption, Adjustment | Additional Paid-in Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit								23,271
Cumulative Effect, Period of Adoption, Adjustment | Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit							$ (2,700)	$ (696)
1.25% Convertible Senior Notes due 2025 | Convertible Debt
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stated interest rate (as a percent)			1.25%	1.25%							1.25%