XML 72 R57.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Investment Securities: (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items] |  |  |
Available-for-sale Securities | $ 41,233 | $ 70,952 |
Investment Maturity Date Range Start | Jan. 01, 2016 |  |
Investment Maturity Date Range End | Dec. 31, 2037 |  |
Investment Income, Interest and Dividend | $ 500 | 400 | $ 400
Federal tax-exempt debt securities [Member] |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |
Available-for-sale Securities | 4,951 | 15,013 |
Corporate Debt Securities [Member] |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |
Available-for-sale Securities | 25,400 | 46,209 |
US Treasury Securities [Member] |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |
Available-for-sale Securities | 7,537 | 0 |
Commercial Paper [Member] |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |
Available-for-sale Securities | 2,097 | 3,846 |
Certificates of deposit [Member] |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |
Available-for-sale Securities | $ 1,248 | $ 5,884 |

X
- Definition The latest maturity date when short-term debt instruments are reported on the Schedule of Investments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 12 -Footnote 2 + Details
Name: | invest_InvestmentMaturityDateRangeEnd1
Namespace Prefix: | invest_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition The earliest maturity date when short-term debt instruments are reported on the Schedule of Investments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 12 -Footnote 2 + Details
Name: | invest_InvestmentMaturityDateRangeStart1
Namespace Prefix: | invest_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49167202&loc=d3e26610-111562 + Details
Name: | us-gaap_AvailableForSaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount before accretion (amortization) of purchase discount (premium) of interest income and dividend income on nonoperating securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.7(a),(b)) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 + Details
Name: | us-gaap_InvestmentIncomeInterestAndDividend
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_NontaxableMunicipalNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CommercialPaperMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |