Company's Repurchase Activities (Parenthetical) (Detail) - shares shares in Millions	Feb. 28, 2018	Jan. 31, 2018
Capital Unit [Line Items]
Company's common units authorized for repurchase	5.5	2.2
Plan III Common Units Repurchase Program
Capital Unit [Line Items]
Company's common units authorized for repurchase	5.5	2.2

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