General Partners and Other Related Parties - Schedule of Withdrawals of Limited Partner Capital (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
General Partners And Other Related Parties Details [Line Items]
Scheduled liquidations, at June 30	$ 43,394		$ 43,394
Limited Partner [Member]
General Partners And Other Related Parties Details [Line Items]
Scheduled liquidations, at June 30	43,394	$ 51,866	43,394	$ 51,866
Limited Partner [Member] | Capital Liquidations-without Penalty [Member]
General Partners And Other Related Parties Details [Line Items]
Total, Capital liquidations	5,371	4,887	10,761	9,788
Limited Partner [Member] | Capital Liquidations-subject to Penalty [Member]
General Partners And Other Related Parties Details [Line Items]
Total, Capital liquidations	1,158	2,118	2,276	4,342
Limited Partner [Member] | Capital Subject to Liquidation Net [Member]
General Partners And Other Related Parties Details [Line Items]
Total, Capital liquidations	$ 6,529	$ 7,005	$ 13,037	$ 14,130