Common Unit Repurchase and Retirement - Company's Repurchase Activities (Detail) - $ / shares shares in Thousands		1 Months Ended					3 Months Ended			84 Months Ended	91 Months Ended
		Apr. 30, 2020	Mar. 31, 2020	Feb. 29, 2020		Jan. 31, 2020	Mar. 31, 2020	Dec. 31, 2019		Sep. 30, 2019	Jan. 31, 2020
Repurchase Plan
Capital Unit [Line Items]
Total Number of Units Purchased			500	122		160	782	1,281		13,340	11,800
Average Price Paid per Unit	[1]		$ 7.76	$ 9.15		$ 9.48	$ 8.33	$ 9.42		$ 8.08
Maximum Number of Units that May Yet Be Purchased			524	1,024	[2]	146	524	306	[3]	956	146
Publicly Announced Plans or Programs As Part of Repurchase Plan
Capital Unit [Line Items]
Total Number of Units Purchased			500	122		160	782	650		10,896
Subsequent Event | Repurchase Plan
Capital Unit [Line Items]
Total Number of Units Purchased		424
Average Price Paid per Unit	[1]	$ 7.71
Maximum Number of Units that May Yet Be Purchased	[4]	100
Subsequent Event | Publicly Announced Plans or Programs As Part of Repurchase Plan
Capital Unit [Line Items]
Total Number of Units Purchased		424

[1] Amount includes repurchase costs.

[2] In February 2020, the Board authorized an increase in the number of Common Units available for repurchase from 0.1 million to 1.1 million.

[3] First quarter of fiscal year 2020 Common Units repurchased include 0.6 million Common Units acquired in a private transaction.

[4] The remaining 0.1 million units under the Repurchase Plan are available for repurchase in privately-negotiated transactions.