2.2.0.25truefalse2410402 - Disclosure - Note 6. Cash, Marketable Securities, and Investments (Details)truefalsefalse1falsefalseUSDfalsefalse1/1/2011 - 3/31/2011 USD ($) USD ($) / shares $D2011Q1http://www.sec.gov/CIK0001274494duration2011-01-01T00:00:002011-03-31T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170PureStandardhttp://www.xbrl.org/2003/instancepure0sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0usdPerShareDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USD_to_EURDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/iso4217EURiso42170USDUSD$2falsefalseUSDfalsefalse12/27/2009 - 3/27/2010 USD ($) USD ($) / shares $D2010Q1http://www.sec.gov/CIK0001274494duration2009-12-27T00:00:002010-03-27T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170usdPerShareDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0PureStandardhttp://www.xbrl.org/2003/instancepure0sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$3falsefalseUSDfalsefalse12/31/2010 USD ($) USD ($) / shares $I2010Q4http://www.sec.gov/CIK0001274494instant2010-12-31T00:00:000001-01-01T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0usdPerShareDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$4falsefalseUSDfalsefalse12/26/2009 USD ($) $I2009Q4http://www.sec.gov/CIK0001274494instant2009-12-26T00:00:000001-01-01T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2true0invest_InvestmentLineItemsinvestfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringLine 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.falsefalseInvestment [Line Items]3false0us-gaap_CashAndCashEquivalentsAtCarryingValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse355725000355725000falsetruefalsefalsefalse2truefalsefalse420886000420886000falsetruefalsefalsefalse3truefalsefalse765689000765689000falsetruefalsefalsefalse4truefalsefalse664499000664499000falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncludes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 falsefalseCash and cash equivalents4false0us-gaap_AvailableForSaleSecuritiesus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse357227000357227000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truefalsefalse348160000348160000falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading. Such securities are reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale Security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain or loss of an Available-for-sale Security that is designated as being hedged in a fair value hedge shall be recognized in earnings during the period of the hedge, as should other than temporary declines in fair value below costs basis.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 16 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 22 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 12 -Subparagraph b Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 13 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 14 falsefalseMarketable securities and investments5false0us-gaap_InvestmentsAndCashus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse712952000712952000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truefalsefalse11138490001113849000falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetarySum of investments and unrestricted cash as of the balance sheet dateNo authoritative reference available.falsefalseTotal cash, cash equivalents, marketable securities, and investments6false0us-gaap_AvailableForSaleSecuritiesGrossRealizedGainsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse100000100000falsefalsefalsefalsefalse2truefalsefalse300000300000falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 21 -Subparagraph a falsefalseAvailable-for-sale securities, gross realized gains7false0us-gaap_AvailableForSaleSecuritiesGrossRealizedLossesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse00falsefalsefalsefalsefalse2truefalsefalse100000100000falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 21 -Subparagraph a falsefalseAvailable-for-sale securities, gross realized losses8false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.firstsolar.com/role/note6.cashmarketablesecuritiesandinvestmentsdetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalse5falsefalseUSDtruefalse{fslr_CashAndCashEquivalentsAxis} : Cash [Member] 3/31/2011 USD ($) $I2011Q1_fslr_CashAndCashEquivalentsAxis_us-gaap_CashMemberhttp://www.sec.gov/CIK0001274494instant2011-03-31T00:00:000001-01-01T00:00:00falsefalseCash [Member]fslr_CashAndCashEquivalentsAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashMemberfslr_CashAndCashEquivalentsAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$6falsefalseUSDtruefalse{fslr_CashAndCashEquivalentsAxis} : Cash [Member] 12/31/2010 USD ($) $I2010Q4_fslr_CashAndCashEquivalentsAxis_us-gaap_CashMemberhttp://www.sec.gov/CIK0001274494instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseCash [Member]fslr_CashAndCashEquivalentsAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashMemberfslr_CashAndCashEquivalentsAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalseCash [Member]9true0invest_InvestmentLineItemsinvestfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringLine 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.falsefalseInvestment [Line Items]10false0us-gaap_CashAndCashEquivalentsAtCarryingValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse317395000317395000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truefalsefalse742200000742200000falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncludes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 falsefalseCash and cash equivalents11false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.firstsolar.com/role/note6.cashmarketablesecuritiesandinvestmentsdetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalse7falsefalseUSDtruefalse{fslr_CashAndCashEquivalentsAxis} : Commercial Paper [Member] 3/31/2011 USD ($) $I2011Q1_fslr_CashAndCashEquivalentsAxis_us-gaap_CommercialPaperMemberhttp://www.sec.gov/CIK0001274494instant2011-03-31T00:00:000001-01-01T00:00:00falsefalseCommercial Paper [Member]fslr_CashAndCashEquivalentsAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CommercialPaperMemberfslr_CashAndCashEquivalentsAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$8falsefalseUSDtruefalse{fslr_CashAndCashEquivalentsAxis} : Commercial Paper [Member] 12/31/2010 USD ($) $I2010Q4_fslr_CashAndCashEquivalentsAxis_us-gaap_CommercialPaperMemberhttp://www.sec.gov/CIK0001274494instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseCommercial Paper [Member]fslr_CashAndCashEquivalentsAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CommercialPaperMemberfslr_CashAndCashEquivalentsAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalseCommercial Paper [Member]12true0invest_InvestmentLineItemsinvestfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringLine 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.falsefalseInvestment [Line Items]13false0us-gaap_CashAndCashEquivalentsAtCarryingValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse49980004998000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truefalsefalse12000001200000falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncludes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 falsefalseCash and cash equivalents14false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.firstsolar.com/role/note6.cashmarketablesecuritiesandinvestmentsdetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalse9falsefalseUSDtruefalse{fslr_CashAndCashEquivalentsAxis} : Corporate Debt Securities Cash Equivalents [Member] 3/31/2011 USD ($) $I2011Q1_fslr_CashAndCashEquivalentsAxis_fslr_CorporateDebtSecuritiesCashEquivalentsMemberhttp://www.sec.gov/CIK0001274494instant2011-03-31T00:00:000001-01-01T00:00:00falsefalseCorporate Debt Securities Cash Equivalents [Member]fslr_CashAndCashEquivalentsAxisxbrldihttp://xbrl.org/2006/xbrldifslr_CorporateDebtSecuritiesCashEquivalentsMemberfslr_CashAndCashEquivalentsAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$10falsefalseUSDtruefalse{fslr_CashAndCashEquivalentsAxis} : Corporate Debt Securities Cash Equivalents [Member] 12/31/2010 USD ($) $I2010Q4_fslr_CashAndCashEquivalentsAxis_fslr_CorporateDebtSecuritiesCashEquivalentsMemberhttp://www.sec.gov/CIK0001274494instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseCorporate Debt Securities Cash Equivalents [Member]fslr_CashAndCashEquivalentsAxisxbrldihttp://xbrl.org/2006/xbrldifslr_CorporateDebtSecuritiesCashEquivalentsMemberfslr_CashAndCashEquivalentsAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalseCorporate Debt Securities Cash Equivalents [Member]15true0invest_InvestmentLineItemsinvestfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringLine 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.falsefalseInvestment [Line Items]16false0us-gaap_CashAndCashEquivalentsAtCarryingValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse5200052000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncludes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. 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Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 falsefalseCash and cash equivalents17false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.firstsolar.com/role/note6.cashmarketablesecuritiesandinvestmentsdetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalse11falsefalseUSDtruefalse{fslr_CashAndCashEquivalentsAxis} : Money Market Funds [Member] 3/31/2011 USD ($) $I2011Q1_fslr_CashAndCashEquivalentsAxis_us-gaap_MoneyMarketFundsMemberhttp://www.sec.gov/CIK0001274494instant2011-03-31T00:00:000001-01-01T00:00:00falsefalseMoney Market Funds [Member]fslr_CashAndCashEquivalentsAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MoneyMarketFundsMemberfslr_CashAndCashEquivalentsAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$12falsefalseUSDtruefalse{fslr_CashAndCashEquivalentsAxis} : Money Market Funds [Member] 12/31/2010 USD ($) $I2010Q4_fslr_CashAndCashEquivalentsAxis_us-gaap_MoneyMarketFundsMemberhttp://www.sec.gov/CIK0001274494instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseMoney Market Funds [Member]fslr_CashAndCashEquivalentsAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MoneyMarketFundsMemberfslr_CashAndCashEquivalentsAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalseMoney Market Funds [Member]18true0invest_InvestmentLineItemsinvestfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringLine items represent financial concepts included in a table. 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Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 falsefalseCash and cash equivalents20false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.firstsolar.com/role/note6.cashmarketablesecuritiesandinvestmentsdetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalse13falsefalseUSDtruefalse{invest_InvestmentAxis} : Certificates of Deposit [Member] 3/31/2011 USD ($) $I2011Q1_invest_InvestmentAxis_us-gaap_CertificatesOfDepositMemberhttp://www.sec.gov/CIK0001274494instant2011-03-31T00:00:000001-01-01T00:00:00falsefalseCertificates of Deposit [Member]invest_InvestmentAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CertificatesOfDepositMemberinvest_InvestmentAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$14falsefalseUSDtruefalse{invest_InvestmentAxis} : Certificates of Deposit [Member] 12/31/2010 USD ($) $I2010Q4_invest_InvestmentAxis_us-gaap_CertificatesOfDepositMemberhttp://www.sec.gov/CIK0001274494instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseCertificates of Deposit [Member]invest_InvestmentAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CertificatesOfDepositMemberinvest_InvestmentAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalseCertificates of Deposit [Member]21true0invest_InvestmentLineItemsinvestfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringLine items represent financial concepts included in a table. 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