| Report Element Information |
| Run date/time: 6/5/2011 7:34:42 AM |
| Report Element Attributes: |
| Report element from taxonomy prefix: | us-gaap |
| US GAAP taxonomy standard label: | us-gaap: Treasury Stock, Shares |
| Filer taxonomy standard label: | Treasury Stock, Shares |
| Documentation: | Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends. |
| Balance type: | |
| Period type: | As of (instant) |
| Report element type: | [Concept] |
| Data type: | Shares (xbrli:sharesItemType) |
| ID: | us-gaap_TreasuryStockShares |
| Name: | us-gaap:TreasuryStockShares |
| Labels of Report Element: (Labels from filer taxonomy, does not include other labels) |
| Role: | Label | Lang |
| Standard label (http://www.xbrl.org/2003/role/label) | Treasury Stock, Shares | en-US |
| References of Report Element, FASB Accounting Standards Codification: |
| Publisher, Name: | Topic | Sub Topic | Glossary | URI |
| FASB, Accounting Standards Codification | 210 | 10 | http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 |
| References of Report Element, SEC Regulation S-X (SX): |
| Publisher, Name: | Number | Section | Paragraph | Subparagraph | Article |
| SEC, Regulation S-X (SX) | 210 | 02 | 29, 30 | 5 |
| References of Report Element, US GAAP Legacy: |
| Publisher: | Name | Number | Chapter | Section | Paragraph | Subparagraph | Article | Clause | Appendix |