Summary of Significant Accounting Policies - Reconciliation of Basic and Diluted Net Loss per Share Attributable to Common Shareholders (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Schedule Of Basic And Diluted Net Income Loss Per Share [Line Items]
Net income (loss)	$ (18,359)	$ (1,485)	$ 2,520	$ 628	$ (19,844)	$ 3,148
Preferred dividends	528				1,057
Net income (loss) attributable to common shareholders	$ (18,887)		$ 2,520		$ (20,901)	$ 3,148
Basic and diluted weighted average common shares outstanding	7,096		1,667		7,090	1,667
Net income (loss) per share attributable to common shareholders	$ (2.66)		$ 1.51		$ (2.95)	$ 1.89
Class A Common Stock
Schedule Of Basic And Diluted Net Income Loss Per Share [Line Items]
Basic and diluted weighted average common shares outstanding	1,683,000		1,667,000		1,682,000	1,667,000
Net income (loss) per share attributable to common shareholders	$ (2.66)		$ 1.51		$ (2.95)	$ 1.89
Class B Common Stock
Schedule Of Basic And Diluted Net Income Loss Per Share [Line Items]
Basic and diluted weighted average common shares outstanding	5,413,000				5,408,000
Net income (loss) per share attributable to common shareholders	$ (2.66)				$ (2.95)