Partnership's Average Interest Rate and Average Debt Balance (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2013
Revolving Credit Facilities
Debt [Line Items]
Average Interest Rate	2.298%
Average Balance	$ 114,955
5.875 Percent Senior Notes due April 2021
Debt [Line Items]
Average Interest Rate	5.875%
Average Balance	350,000
6.125 Percent Senior Notes due July 2022
Debt [Line Items]
Average Interest Rate	6.125%
Average Balance	750,000
4.875 Percent Senior Notes due May 2023
Debt [Line Items]
Average Interest Rate	4.875%
Average Balance	$ 1,400,000

The average effective interest rate during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration