Liability for Estimated Expense in Excess of Estimated Income During Liquidation - Summary of Accrued Income and Expenses Expected to be Incurred During Liquidation (Details) $ in Thousands	4 Months Ended
	Dec. 31, 2019 USD ($)
Summary Of Liquidation [Line Items]
Beginning Balance, September 1, 2019	$ (77,859)
Cash Payments (Receipts)	58,898
Remeasurement of Assets and Liabilities	587
Reclassification for Expenses Incurred and Income Earned	8,401
Ending Balance, December 31, 2019	(9,973)
Rental Income
Summary Of Liquidation [Line Items]
Beginning Balance, September 1, 2019	7,594
Cash Payments (Receipts)	(6,253)
Remeasurement of Assets and Liabilities	487
Reclassification for Expenses Incurred and Income Earned	(790)
Ending Balance, December 31, 2019	1,038
Property Costs
Summary Of Liquidation [Line Items]
Beginning Balance, September 1, 2019	(1,159)
Cash Payments (Receipts)	922
Remeasurement of Assets and Liabilities	(1,100)
Reclassification for Expenses Incurred and Income Earned	64
Ending Balance, December 31, 2019	(1,273)
General and Administrative
Summary Of Liquidation [Line Items]
Beginning Balance, September 1, 2019	(27,620)
Cash Payments (Receipts)	10,678
Remeasurement of Assets and Liabilities	1,699
Reclassification for Expenses Incurred and Income Earned	9,044
Ending Balance, December 31, 2019	(6,199)
Related Party Fees
Summary Of Liquidation [Line Items]
Beginning Balance, September 1, 2019	(51,693)
Cash Payments (Receipts)	49,857
Remeasurement of Assets and Liabilities	836
Reclassification for Expenses Incurred and Income Earned	83
Ending Balance, December 31, 2019	(917)
Cost of Real Estate Investment Sales
Summary Of Liquidation [Line Items]
Beginning Balance, September 1, 2019	(4,981)
Cash Payments (Receipts)	3,694
Remeasurement of Assets and Liabilities	(1,335)
Ending Balance, December 31, 2019	$ (2,622)

SMTA Liquidating Trust 10-K