Summary of Significant Accounting Policies - Impact of Adoption of Previously Reported Amounts of Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Jan. 01, 2020		Dec. 31, 2019
Right-of-use assets		$ 6,149	$ 6,835	[1],[2]
Deferred rent					$ 1,313
Operating lease liabilities		16,037	2,251	[3]
Operating lease liabilities		$ 2,497	15,441	[3]
Prior to Adoption of New Leasing Standards
Deferred rent	[2]		1,313
Deferred rent	[2]		9,544
Adjustment for Adoption of New Leasing Standards
Right-of-use assets	[1],[2]		6,835
Deferred rent	[2]		1,313
Deferred rent	[2]		(9,544)
Operating lease liabilities	[3]		2,251
Operating lease liabilities	[3]		$ 15,441

[1] Represents capitalization of operating right-of-use assets

[2] Represents reclassification of deferred rent and incentives as a reduction to operating right-of-use assets

[3] Represents recognition of operating lease liabilities