General Partners and Other Related Parties - Schedule of Withdrawals of Limited Partner Capital (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
General Partners And Other Related Parties Details [Line Items]
Scheduled liquidations, at September 30	$ 43,769		$ 43,769
Limited Partner [Member]
General Partners And Other Related Parties Details [Line Items]
Scheduled liquidations, at September 30	43,769	$ 50,545	43,769	$ 50,545
Limited Partner [Member] | Capital Liquidations-without Penalty [Member]
General Partners And Other Related Parties Details [Line Items]
Total, Capital liquidations	4,863	5,109	15,624	14,897
Limited Partner [Member] | Capital Liquidations-subject to Penalty [Member]
General Partners And Other Related Parties Details [Line Items]
Total, Capital liquidations	960	2,082	3,236	6,424
Limited Partner [Member] | Capital Subject to Liquidation Net [Member]
General Partners And Other Related Parties Details [Line Items]
Total, Capital liquidations	$ 5,823	$ 7,191	$ 18,860	$ 21,321