Equity - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Aug. 18, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Payment of dividends to Class A common stockholders			$ 7,917,000	$ 7,776,000
Distributions paid	$ 9,674,000	$ 20,130,000	23,409,000	$ 28,108,000
Total cost	$ 395,000		395,000
Class A Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Payment of dividends to Class A common stockholders			$ 7,900,000
Dividends paid (in dollars per share)	$ 0.18125	$ 0.18125	$ 0.54375	$ 0.54375
Share repurchase program, amount authorized					$ 20,000,000.0
Repurchased shares (in shares)	45,148		45,148
Repurchased stock per share (in dollars per share)	$ 8.75		$ 8.75
Total cost	$ 400,000		$ 400,000
Class B Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Distributions paid			$ 11,300,000
Shares excluded from computation of diluted earnings per share (in shares)	20,800,000		20,800,000