2.4.0.82131100 - Disclosure - Available-for-Sale Investmentstruefalsefalse1false falsefalseD2013Q2YTDhttp://www.sec.gov/CIK0000731657duration2013-01-01T00:00:002013-06-30T00:00:001true 1spir_AvailableForSaleInvestmentsAbstractspir_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Available-for-Sale Investments [Abstract]2false 2us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-weight:bold;">Available-for-Sale Investments</font></div><div style="line-height:120%;text-align:justify;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;"><br clear="none"/></font></div><div style="line-height:120%;text-align:justify;text-indent:36px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">Available-for-sale investments consist of assets held as part of the Spire Corporation Non-Qualified Deferred Compensation Plan. These investments have been classified as available-for-sale investments and are reported at fair value, with unrealized gains and losses included in accumulated other comprehensive income. The unrealized gain on these marketable securities was </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">$329 thousand</font><font style="font-family:inherit;font-size:10pt;"> and </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">$222 thousand</font><font style="font-family:inherit;font-size:10pt;"> as of </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">June&#160;30, 2013</font><font style="font-family:inherit;font-size:10pt;"> and </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">December&#160;31, 2012</font><font style="font-family:inherit;font-size:10pt;">, respectively. Additionally, the Company settled </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">$84 thousand</font><font style="font-family:inherit;font-size:10pt;"> of accrued liabilities through issuance of common stock to available-for-sale investments during the </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">six</font><font style="font-family:inherit;font-size:10pt;"> month period ended </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">June&#160;30, 2013</font><font style="font-family:inherit;font-size:10pt;">.</font></div></div>falsefalsefalsenonnum:textBlockItemTypenaThe entire disclosure for investments in certain debt and equity securities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 3, 19, 20, 21, 22, 137 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -Glossary Debt Security -URI http://asc.fasb.org/extlink&oid=6509901 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27161-111563 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27357-111563 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27290-111563 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27405-111563 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27232-111563 Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -Glossary Equity Security -URI http://asc.fasb.org/extlink&oid=6511694 false0Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]falseAvailable-for-Sale InvestmentsUnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.spirecorp.com/role/AvailableForSaleInvestments12