Condensed Consolidating Financial Information, Guarantors and Non-Guarantors (Details)	12 Months Ended
Dec. 31, 2011
Limited partner [Member]
Related Party Transaction [Line Items]
Noncontrolling interest, ownership percentage by parent	52.00%
Guarantor subsidiaries [Member]
Related Party Transaction [Line Items]
Subsidiary or equity method investee, cumulative percentage ownership after all transactions	100.00%

Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions.

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section H

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