Document Information	12 Months Ended
Dec. 31, 2011
Document Type	10-K
Document Period End Date	Dec. 31, 2011
Amendment Flag	false

The type of document being provided (such as 10-K, 10-Q, N-1A, etc). The document type should be limited to the same value as the supporting SEC submission type. The acceptable values are as follows: S-1, S-3, S-4, S-11, F-1, F-3, F-4, F-9, F-10, 6-K, 8-K, 10, 10-K, 10-Q, 20-F, 40-F, N-1A, 485BPOS, NCSR, N-Q, and Other.

No definition available.

Name:	dei_DocumentType
Namespace Prefix:	dei_
Data Type:	us-types:SECReportItemType
Balance Type:	na
Period Type:	duration