Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Jan. 01, 2021	Dec. 31, 2020	Jun. 30, 2020	May 04, 2020	Mar. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred income tax liabilities, net	$ (63,877)					$ (5,415)
Deferred tax assets, valuation allowance	15,500
Convertible senior notes, net	531,077					168,120
Accumulated deficit	(1,148,358)			$ (843,714)		(694,294)	$ (654,229)		$ (505,043)	$ (507,408)
Foreign Tax Authority
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred tax assets, valuation allowance	3,400					2,600
Additional Paid-in Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit	(1,101,298)			(872,350)		(701,357)	(679,235)		(525,929)	(520,278)
Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit	$ (47,270)			$ 28,603		7,185	$ 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%