Cash Distributions to Limited Partners - Additional Information (Detail) (USD $)	3 Months Ended
Dec. 31, 2012
Partners Capital And Distributions [Line Items]
Distributions declared per limited partnership unit	$ 4.37
Declaration to the limited partner, declaration date	Jan. 31, 2013
Distributions to the limited partner, distribution date	Feb. 28, 2013

Date of declaration for distribution of cash, stock, or units to a member or limited partner of limited liability company (LLC) or limited partnership (LP), in CCYY-MM-DD format.

No definition available.

Name:	us-gaap_DistributionMadeToMemberOrLimitedPartnerDeclarationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration