Partnership's Repurchase Activities (Parenthetical) (Detail) In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014
Capital Unit [Line Items]
Partnership's common units authorized for repurchase	6,044
Private Transaction
Capital Unit [Line Items]
Partnership's common units authorized for repurchase	1,150	1,450

The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

No definition available.

Name:	us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant