Related Party Transactions - Management Agreement (Details) - SP General Services LLC - USD ($) $ in Thousands	3 Months Ended		4 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Related Party Transaction [Line Items]
Management fee percentage, quarterly basis (as a percent)				1.50%
Management agreement renewal, term (in years)				1 year
Notice period prior to management agreement renewal, period (in days)				60 days
Management Fee
Related Party Transaction [Line Items]
Waived management fee			$ 2,186
Services fees and reimbursable expenses	$ (591)	$ 1,975		$ 1,182	$ 3,908
Unpaid amount for management fee	591		591	591		$ 27
Reimbursable Expenses
Related Party Transaction [Line Items]
Services fees and reimbursable expenses	210	$ 1,429		1,152	$ 3,569
Deferred fees payable to related party	$ 1,210		$ 1,210	$ 1,210		$ 409