Common Unit Repurchase and Retirement - Company's Repurchase Activities (Detail) - $ / shares shares in Thousands		1 Months Ended					3 Months Ended		84 Months Ended	85 Months Ended
		Jan. 31, 2020	Dec. 31, 2019		Nov. 30, 2019	Oct. 31, 2019	Dec. 31, 2019		Sep. 30, 2019	Jul. 31, 2019
Repurchase Plan
Capital Unit [Line Items]
Total Number of Units Purchased			797		261	223	1,281		13,340	9,500
Average Price Paid per Unit	[1]		$ 9.42		$ 9.39	$ 9.44	$ 9.42		$ 8.08
Maximum Number of Units that May Yet Be Purchased			306	[2]	472	733	306	[2]	956
Publicly Announced Plans or Programs As Part of Repurchase Plan
Capital Unit [Line Items]
Total Number of Units Purchased			166		261	223	650		10,896
Subsequent Event | Repurchase Plan
Capital Unit [Line Items]
Total Number of Units Purchased		160
Average Price Paid per Unit	[1]	$ 9.48
Maximum Number of Units that May Yet Be Purchased	[3]	146
Subsequent Event | Publicly Announced Plans or Programs As Part of Repurchase Plan
Capital Unit [Line Items]
Total Number of Units Purchased		160

[1] Amount includes repurchase costs.

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

[3] Of the total available for repurchase, less than 0.1 million are available for repurchase in open market transactions and 0.1 million are available for repurchase in privately-negotiated transactions.