Common Unit Repurchase and Retirement - Company's Repurchase Activities (Detail) - $ / shares shares in Thousands		1 Months Ended					3 Months Ended		98 Months Ended	108 Months Ended
		Jan. 31, 2022	Dec. 31, 2021		Nov. 30, 2021	Oct. 31, 2021	Dec. 31, 2021		Aug. 31, 2020	Sep. 30, 2021
Repurchase Plan
Capital Unit [Line Items]
Total Number of Units Purchased			670		161	273	1,104		14,400	21,979
Average Price Paid per Unit	[1]		$ 10.56		$ 10.99	$ 10.67	$ 10.65			$ 8.60
Maximum Number of Units that May Yet Be Purchased			2,157	[2]	2,414	2,575	2,157	[2]		2,848
Repurchase Plan | Subsequent Event
Capital Unit [Line Items]
Total Number of Units Purchased		264
Average Price Paid per Unit	[1]	$ 10.59
Maximum Number of Units that May Yet Be Purchased	[3]	1,893
Publicly Announced Plans or Programs As Part of Repurchase Plan
Capital Unit [Line Items]
Total Number of Units Purchased			257		161	273	691			17,504
Publicly Announced Plans or Programs As Part of Repurchase Plan | Subsequent Event
Capital Unit [Line Items]
Total Number of Units Purchased		264

[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 1.6 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