Common Unit Repurchase and Retirement - Company's Repurchase Activities (Detail) - $ / shares		1 Months Ended				3 Months Ended				98 Months Ended	108 Months Ended
		Jul. 31, 2022	Jun. 30, 2022	May 31, 2022	Apr. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021		Aug. 31, 2020	Sep. 30, 2021
Repurchase Plan
Capital Unit [Line Items]
Total Number of Units Purchased			198,000	124,000	165,000	487,000	992,000	1,104,000		14,400,000	21,979,000
Average Price Paid per Unit	[1]		$ 10.00	$ 10.59	$ 11.10	$ 10.52	$ 10.50	$ 10.65			$ 8.60
Maximum Number of Units that May Yet Be Purchased			678,000	876,000	1,000,000	678,000	1,165,000	2,157,000	[2]		2,848,000
Repurchase Plan | Subsequent Event
Capital Unit [Line Items]
Total Number of Units Purchased		126,000
Average Price Paid per Unit	[1]	$ 9.73
Maximum Number of Units that May Yet Be Purchased	[3]	552
Publicly Announced Plans or Programs As Part of Repurchase Plan
Capital Unit [Line Items]
Total Number of Units Purchased			198,000	124,000	165,000	487,000	992,000	691,000			17,504,000
Publicly Announced Plans or Programs As Part of Repurchase Plan | Subsequent Event
Capital Unit [Line Items]
Total Number of Units Purchased		126,000

[1] Amount includes repurchase costs.

[2] On December 30, 2021, the Company purchased 0.4 million Common Units in a private transaction for aggregate consideration of approximately $4.4 million. The approved purchase was made outside of the Company’s unit repurchase plan.

[3] Of the total available for repurchase, approximately 0.3 million units are available for repurchase in open market transactions and 0.3 million units are available for repurchase in privately-negotiated transactions, under the Repurchase Plan.