Certain provisions of the partnership agreement (Details Textuals 1) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2012
Distribution Made to Member or Limited Partner [Line Items]
8 7/8% Senior unsecured notes due 2018 (2018 Notes)	8 7/8%	8 7/8%
Percentage Of Cash Avaliable For Distribution	100.00%	100.00%
Number of days from end of quarter for distribution		45
Incentive Distribution, Distribution	$ 1.1	$ 2.1
13% GP distribution member
Distribution Made to Member or Limited Partner [Line Items]
Incentive Distibution Excess Per Unit Amount		$ 0.25
23% Distribution Member
Distribution Made to Member or Limited Partner [Line Items]
Incentive Distibution Excess Per Unit Amount		$ 0.3125
48% distribution member
Distribution Made to Member or Limited Partner [Line Items]
Incentive Distibution Excess Per Unit Amount		$ 0.375
Common And Preferred [Member]
Distribution Made to Member or Limited Partner [Line Items]
Percentage Of Distribution Allocated to Common Units	98.00%	98.00%
General Partner [Member]
Distribution Made to Member or Limited Partner [Line Items]
Percentage of distribution allocated to partner	2.00%	2.00%
General Partner [Member] \| 13% GP distribution member
Distribution Made to Member or Limited Partner [Line Items]
Incentive Distribution Percentage Levels		13.00%
General Partner [Member] \| 23% Distribution Member
Distribution Made to Member or Limited Partner [Line Items]
Incentive Distribution Percentage Levels		23.00%
General Partner [Member] \| 48% distribution member
Distribution Made to Member or Limited Partner [Line Items]
Incentive Distribution Percentage Levels		48.00%

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Amount of incentive obligation paid in cash or stock during the period to a limited liability corporation managing member or limited partnership general partner.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 07-4

-Paragraph 2, 9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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- Definition

Per-share or per-unit amount of incentive dividend declared and paid to managing member in excess of regular amount

+ References

No definition available.

+ Details

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- Definition

Different percentage level for each distribution excess allocated to General Partners

+ References

No definition available.

+ Details

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- Definition

Per Partnership agreement, the number of days following the end of quarter to make distribution of avaliable cash

+ References

No definition available.

+ Details

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- Definition

Per partnership agreement the percentage of cash to be distributed

+ References

No definition available.

+ Details

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- Definition

Percentage of the total distribution allocated to the common unit holder of the Partnership

+ References

No definition available.

+ Details

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- Definition

General Partner's ownership percentage in Limited Partnership

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Interest rate on senior unsecured notes "2018 Notes"

+ References

No definition available.

+ Details

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