XML 16 R33.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Marketable Securities: (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2012
Marketable Securities: |
Reconciliation of marketable securities |
|  | June 30, 2012 |  | December 31, 2011 |
--- | --- | --- | --- | --- | ---
Government debt securities, at par value |  | $ | 24,458 |  | $ | 25,147 |
Less discount |  |  | (201 | ) |  | (314 | )
|  |  | 24,257 |  |  | 24,833 |
Unrealized gain |  |  | 1,228 |  |  | 1,803 |
Fair value (Level 1 measurement) |  | $ | 25,485 |  | $ | 26,636 |
Future contractual maturities of marketable securities |
1 year or less |  | $ | 1,378 |
2 to 5 years |  |  | 23,080 |
|  | $ | 24,458 |

X
- Definition A table of investments, shown as a text block. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 + Details
Name: | invest_InvestmentTableTextBlock
Namespace Prefix: | invest_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of maturities of an entity's investments as well as any other information pertinent to the investments. + References No definition available. + Details
Name: | us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration