Income Taxes - Components of Income Tax Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ (173)	$ (70)	$ (60)
State and local	(1,411)	(1,309)	(1,668)
Benefit (provision) for income taxes	$ (1,584)	$ (1,379)	$ (1,728)