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A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseinvestment Objective, Primary6false0rr_ExpenseHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Fees and ExpensesfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Fee Table Includes the following information, in plain English under rule 421(d) under the Securities Act, after Item 2 Fees and expenses of the Fund This table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Shareholder Fees (fees paid directly from your investment) Example This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be You would pay the following expenses if you did not redeem your shares The Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher. Portfolio Turnover The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was __% of the average value of its whole portfolio. Instructions. A.3.instructions.6 New Funds. For purposes of this Item, a "New Fund" is a Fund that does not include in Form N-1A financial statements reporting operating results or that includes financial statements for the Fund's initial fiscal year reporting operating results for a period of 6 months or less. 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More information about these and other waivers and reductions is available from your financial intermediary and in "Sales Charges and Waivers or Reductions" on page 7 of the fund's prospectus and "Waivers of Sales Charges" on page 13 of the fund's statement of additional information Part I.</pre>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Include the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown.The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount. 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available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>A</pre>falsefalsefalsetruefalse2falsefalsefalse00<pre>B</pre>falsefalsefalsetruefalse3falsefalsefalse00<pre>C</pre>falsefalsefalsetruefalse4falsefalsefalse00<pre>I</pre>falsefalsefalsetruefalse5falsefalsefalse00<pre>R1</pre>falsefalsefalsetruefalse6falsefalsefalse00<pre>R2</pre>falsefalsefalsetruefalse7falsefalsefalse00<pre>R3</pre>falsefalsefalsetruefalse8falsefalsefalse00<pre>R4</pre>falsefalsefalsetruefalseOtherus-types:textBlockItemTypestringAnnual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 7 -Subsection table falsefalseOperating Expenses, Column Name0rr_OperatingExpensesColumnNametruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>A</pre>Afalsefalsefalsetruefalse2falsefalsefalse00<pre>B</pre>Bfalsefalsefalsetruefalse3falsefalsefalse00<pre>C</pre>Cfalsefalsefalsetruefalse4falsefalsefalse00<pre>I</pre>Ifalsefalsefalsetruefalse5falsefalsefalse00<pre>R1</pre>R1falsefalsefalsetruefalse6falsefalsefalse00<pre>R2</pre>R2falsefalsefalsetruefalse7falsefalsefalse00<pre>R3</pre>R3falsefalsefalsetruefalse8falsefalsefalse00<pre>R4</pre>R4falsefalsefalsetruefalseOthernanafalsefalseOperating Expenses, Column Name2falseRowprimaryElement*4false0rr_ManagementFeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00750.0075falsefalsefalsetruefalse2truetruetrue0.00750.0075falsefalsefalsetruefalse3truetruetrue0.00750.0075falsefalsefalsetruefalse4truetruetrue0.00750.0075falsefalsefalsetruefalse5truetruetrue0.00750.0075falsefalsefalsetruefalse6truetruetrue0.00750.0075falsefalsefalsetruefalse7truetruetrue0.00750.0075falsefalsefalsetruefalse8truetruetrue0.00750.0075falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureManagement Fees include investment advisory fees (including any fees based on the Fund's performance), any other management fees payable to the investment adviser or its affiliates, and administrative fees payable to the investment adviser or its affiliates that are not included as "Other Expenses."Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph a -Subsection instructions falsefalseManagement Fee0rr_ManagementFeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00750.0075falsefalsefalsetruefalse2truetruetrue0.00750.0075falsefalsefalsetruefalse3truetruetrue0.00750.0075falsefalsefalsetruefalse4truetruetrue0.00750.0075falsefalsefalsetruefalse5truetruetrue0.00750.0075falsefalsefalsetruefalse6truetruetrue0.00750.0075falsefalsefalsetruefalse7truetruetrue0.00750.0075falsefalsefalsetruefalse8truetruetrue0.00750.0075falsefalsefalsetruefalseOthernanafalsefalseManagement Fee3falseRowprimaryElement*5false0rr_DistributionAndService12b1FeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00250.0025falsefalsefalsetruefalse2truetruetrue0.01000.0100falsefalsefalsetruefalse3truetruetrue0.01000.0100falsefalsefalsetruefalse4truetruetrue0.00000.0000falsefalsefalsetruefalse5truetruetrue0.01000.0100falsefalsefalsetruefalse6truetruetrue0.00500.0050falsefalsefalsetruefalse7truetruetrue0.00250.0025falsefalsefalsetruefalse8truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureDistribution [and/or Service] (12b-1) Fees" include all distribution or other expenses incurred during the most recent fiscal year under a plan adopted pursuant to rule 12b-1 [17 CFR 270.12b-1]. Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 9 -Subsection table falsefalseDistribution and/or Service (12b-1) Fees0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00250.0025falsefalsefalsetruefalse2truetruetrue0.01000.0100falsefalsefalsetruefalse3truetruetrue0.01000.0100falsefalsefalsetruefalse4truetruetrue0.00000.0000falsefalsefalsetruefalse5truetruetrue0.01000.0100falsefalsefalsetruefalse6truetruetrue0.00500.0050falsefalsefalsetruefalse7truetruetrue0.00250.0025falsefalsefalsetruefalse8truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalseDistribution and/or Service (12b-1) Fees4falseRowprimaryElement*6false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00300.0030falsefalsefalsetruefalse2truetruetrue0.00300.0030falsefalsefalsetruefalse3truetruetrue0.00300.0030falsefalsefalsetruefalse4truetruetrue0.00300.0030falsefalsefalsetruefalse5truetruetrue0.00300.0030falsefalsefalsetruefalse6truetruetrue0.00300.0030falsefalsefalsetruefalse7truetruetrue0.00300.0030falsefalsefalsetruefalse8truetruetrue0.00300.0030falsefalsefalsetruefalseOtherrr:NonNegativePure4Typepure"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph c -Clause i -Subsection instructions falsefalseOther Expenses0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00300.0030falsefalsefalsetruefalse2truetruetrue0.00300.0030falsefalsefalsetruefalse3truetruetrue0.00300.0030falsefalsefalsetruefalse4truetruetrue0.00300.0030falsefalsefalsetruefalse5truetruetrue0.00300.0030falsefalsefalsetruefalse6truetruetrue0.00300.0030falsefalsefalsetruefalse7truetruetrue0.00300.0030falsefalsefalsetruefalse8truetruetrue0.00300.0030falsefalsefalsetruefalseOthernanafalsefalseOther Expenses5falseRowprimaryElement*7false0rr_ExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.01300.0130falsefalsefalsetruefalse2truetruetrue0.02050.0205falsefalsefalsetruefalse3truetruetrue0.02050.0205falsefalsefalsetruefalse4truetruetrue0.01050.0105falsefalsefalsetruefalse5truetruetrue0.02050.0205falsefalsefalsetruefalse6truetruetrue0.01550.0155falsefalsefalsetruefalse7truetruetrue0.01300.0130falsefalsefalsetruefalse8truetruetrue0.01050.0105falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses. If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds. If the prospectus offers more than one Class of a Multiple Class Fund or more than one Feeder Fund that invests in the same Master Fund, provide a separate response for each Class or Feeder Fund. Base the percentages of "Annual Fund Operating Expenses" on amounts incurred during the Fund's most recent fiscal year, but include in expenses amounts that would have been incurred absent expense reimbursement or fee waiver arrangements. If the Fund has changed its fiscal year and, as a result, the most recent fiscal year is less than three months, use the fiscal year prior to the most recent fiscal year as the basis for determining "Annual Fund Operating Expenses."Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph d -Subsection instructions falsefalseTotal Annual Fund Operating Expenses0rr_ExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.01300.0130falsefalsefalsetruefalse2truetruetrue0.02050.0205falsefalsefalsetruefalse3truetruetrue0.02050.0205falsefalsefalsetruefalse4truetruetrue0.01050.0105falsefalsefalsetruefalse5truetruetrue0.02050.0205falsefalsefalsetruefalse6truetruetrue0.01550.0155falsefalsefalsetruefalse7truetruetrue0.01300.0130falsefalsefalsetruefalse8truetruetrue0.01050.0105falsefalsefalsetruefalseOthernanafalsefalseTotal Annual Fund Operating Expenses6falseRowprimaryElement*8false0rr_FeeWaiverOrReimbursementOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue-0.0015-0.0015[1]falsefalsefalsetruefalse2truetruetrue-0.0015-0.0015[1]falsefalsefalsetruefalse3truetruetrue-0.0015-0.0015[1]falsefalsefalsetruefalse4truetruetrue-0.0015-0.0015[1]falsefalsefalsetruefalse5truetruetrue-0.0015-0.0015[1]falsefalsefalsetruefalse6truetruetrue-0.0015-0.0015[1]falsefalsefalsetruefalse7truetruetrue-0.0015-0.0015[1]falsefalsefalsetruefalse8truetruetrue-0.0015-0.0015[1]falsefalsefalsetruefalseOtherrr:NonPositivePure4TypepureTotal Annual Fund Operating Expenses. If there were expense reimbursement or fee waiver arrangements that reduced any Fund operating expenses and will continue to reduce them for no less than one year from the effective date of the Fund's registration statement, a Fund may add two captions to the table one caption showing the amount of the expense reimbursement or fee waiver, and a second caption showing the Fund's net expenses after subtracting the fee reimbursement or expense waiver from the total fund operating expenses. The Fund should place these additional captions directly below the "Total Annual Fund Operating Expenses" caption of the table and should use appropriate descriptive captions, such as "Fee Waiver [and/or Expense Reimbursement]" and "Total Annual Fund Operating Expenses After Fee Waiver [and/or Expense Reimbursement]," respectively. If the Fund provides this disclosure, also disclose the period for which the expense reimbursement or fee waiver arrangement is expected to continue, and briefly describe who can terminate the arrangement and under what circumstances.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseFee Reductions and /or Expense Reimbursements0rr_FeeWaiverOrReimbursementOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1truetruetrue-0.0015-0.0015falsefalsefalsetruefalse2truetruetrue-0.0015-0.0015falsefalsefalsetruefalse3truetruetrue-0.0015-0.0015falsefalsefalsetruefalse4truetruetrue-0.0015-0.0015falsefalsefalsetruefalse5truetruetrue-0.0015-0.0015falsefalsefalsetruefalse6truetruetrue-0.0015-0.0015falsefalsefalsetruefalse7truetruetrue-0.0015-0.0015falsefalsefalsetruefalse8truetruetrue-0.0015-0.0015falsefalsefalsetruefalseOthernanafalsefalseFee Reductions and /or Expense Reimbursements7falseRowprimaryElement*9false0rr_NetExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.01150.0115falsefalsefalsetruefalse2truetruetrue0.01900.0190falsefalsefalsetruefalse3truetruetrue0.01900.0190falsefalsefalsetruefalse4truetruetrue0.00900.0090falsefalsefalsetruefalse5truetruetrue0.01900.0190falsefalsefalsetruefalse6truetruetrue0.01400.0140falsefalsefalsetruefalse7truetruetrue0.01150.0115falsefalsefalsetruefalse8truetruetrue0.00900.0090falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseTotal Annual Fund Operating Expenses After Fee Reductions and/or Expense Reimbursements0rr_NetExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.01150.0115falsefalsefalsetruefalse2truetruetrue0.01900.0190falsefalsefalsetruefalse3truetruetrue0.01900.0190falsefalsefalsetruefalse4truetruetrue0.00900.0090falsefalsefalsetruefalse5truetruetrue0.01900.0190falsefalsefalsetruefalse6truetruetrue0.01400.0140falsefalsefalsetruefalse7truetruetrue0.01150.0115falsefalsefalsetruefalse8truetruetrue0.00900.0090falsefalsefalsetruefalseOthernanafalsefalseTotal Annual Fund Operating Expenses After Fee Reductions and/or Expense Reimbursements1MFS agreed in writing to reduce its management fee to 0.60% of the fund's average daily net assets annually until modified by a vote of the fund's Board of Trustees, but such agreement will continue until at least March 31, 2012.87Annual Fund Operating Expenses MFS Growth FundUnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No authoritative reference available.falsefalseAnnual Fund Operating Expenses [Table]12false0rr_ExpenseExampleHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00ExamplefalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringHeading for Expense Example.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example, Heading13false0rr_ExpenseExampleNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes that: you invest $10,000 in the fund for the time periods indicated and you redeem your shares at the end of the time periods (unless otherwise indicated); your investment has a 5% return each year; and the fund's operating expenses remain the same.</pre>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThe Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection example falsefalseExpense Example, Narrative14false0rr_ExpenseExampleByYearCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Although your actual costs will likely be higher or lower, under these assumptions your costs would be:falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example, By Year, Caption15false0rr_ExpenseExampleWithRedemptionTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://www.mfs.com/role/ExpenseExample_S000002419Member column dei_LegalEntityAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div>falsefalse<div style="display:none">~ http://www.mfs.com/role/ExpenseExample_S000002419Member column dei_LegalEntityAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div>truehttp://www.mfs.com/role/ExpenseExample_S000002419Memberfalsefalse0115 - Schedule - Expense Example {Transposed}truefalsefalse1falseColumnprimaryElement*3false0rr_ExpenseExampleByYearColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>Class A Shares</pre>falsefalsefalsetruefalse2falsefalsefalse00<pre>Class B Shares assuming redemption at end of period</pre>falsefalsefalsetruefalse3falsefalsefalse00<pre>Class C Shares assuming redemption at end of period</pre>falsefalsefalsetruefalse4falsefalsefalse00<pre>Class I Shares</pre>falsefalsefalsetruefalse5falsefalsefalse00<pre>Class R1 Shares</pre>falsefalsefalsetruefalse6falsefalsefalse00<pre>Class R2 Shares</pre>falsefalsefalsetruefalse7falsefalsefalse00<pre>Class R3 Shares</pre>falsefalsefalsetruefalse8falsefalsefalse00<pre>Class R4 Shares</pre>falsefalsefalsetruefalseOtherus-types:textBlockItemTypestringThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example, By Year, Column NamefalseUSDfalsefalse$2falseColumnprimaryElement*4false0rr_ExpenseExampleYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue685685falsefalsefalsetruefalse2truefalsetrue593593falsefalsefalsetruefalse3truefalsetrue293293falsefalsefalsetruefalse4truefalsetrue9292falsefalsefalsetruefalse5truefalsetrue193193falsefalsefalsetruefalse6truefalsetrue143143falsefalsefalsetruefalse7truefalsetrue117117falsefalsefalsetruefalse8truefalsetrue9292falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example, With Redemption, 1 YearfalseUSDfalsefalse$3falseColumnprimaryElement*5false0rr_ExpenseExampleYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue949949falsefalsefalsetruefalse2truefalsetrue928928falsefalsefalsetruefalse3truefalsetrue628628falsefalsefalsetruefalse4truefalsetrue319319falsefalsefalsetruefalse5truefalsetrue628628falsefalsefalsetruefalse6truefalsetrue475475falsefalsefalsetruefalse7truefalsetrue397397falsefalsefalsetruefalse8truefalsetrue319319falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example, With Redemption, 3 YearsfalseUSDfalsefalse$4falseColumnprimaryElement*6false0rr_ExpenseExampleYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue12331233falsefalsefalsetruefalse2truefalsetrue12901290falsefalsefalsetruefalse3truefalsetrue10901090falsefalsefalsetruefalse4truefalsetrue565565falsefalsefalsetruefalse5truefalsetrue10901090falsefalsefalsetruefalse6truefalsetrue831831falsefalsefalsetruefalse7truefalsetrue699699falsefalsefalsetruefalse8truefalsetrue565565falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example, With Redemption, 5 YearsfalseUSDfalsefalse$5falseColumnprimaryElement*7false0rr_ExpenseExampleYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue20402040falsefalsefalsetruefalse2truefalsetrue21752175falsefalsefalsetruefalse3truefalsetrue23672367falsefalsefalsetruefalse4truefalsetrue12691269falsefalsefalsetruefalse5truefalsetrue23672367falsefalsefalsetruefalse6truefalsetrue18331833falsefalsefalsetruefalse7truefalsetrue15551555falsefalsefalsetruefalse8truefalsetrue12691269falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example, With Redemption, 10 YearsfalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseArr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006430Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundAiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>Class A Shares</pre>Class A Sharesfalsefalsefalsetruefalse2truefalsetrue685685falsefalsefalsetruefalse3truefalsetrue949949falsefalsefalsetruefalse4truefalsetrue12331233falsefalsefalsetruefalse5truefalsetrue20402040falsefalsefalsetruefalseOthernanafalsefalseA2falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseBrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006435Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundBiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>Class B Shares assuming redemption at end of period</pre>Class B Shares assuming redemption at end of periodfalsefalsefalsetruefalse2truefalsetrue593593falsefalsefalsetruefalse3truefalsetrue928928falsefalsefalsetruefalse4truefalsetrue12901290falsefalsefalsetruefalse5truefalsetrue21752175falsefalsefalsetruefalseOthernanafalsefalseB3falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseCrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006436Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundCiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>Class C Shares assuming redemption at end of period</pre>Class C Shares assuming redemption at end of periodfalsefalsefalsetruefalse2truefalsetrue293293falsefalsefalsetruefalse3truefalsetrue628628falsefalsefalsetruefalse4truefalsetrue10901090falsefalsefalsetruefalse5truefalsetrue23672367falsefalsefalsetruefalseOthernanafalsefalseC4falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseIrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006437Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundIiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>Class I Shares</pre>Class I Sharesfalsefalsefalsetruefalse2truefalsetrue9292falsefalsefalsetruefalse3truefalsetrue319319falsefalsefalsetruefalse4truefalsetrue565565falsefalsefalsetruefalse5truefalsetrue12691269falsefalsefalsetruefalseOthernanafalsefalseI5falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseR1rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006439Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundR1iso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>Class R1 Shares</pre>Class R1 Sharesfalsefalsefalsetruefalse2truefalsetrue193193falsefalsefalsetruefalse3truefalsetrue628628falsefalsefalsetruefalse4truefalsetrue10901090falsefalsefalsetruefalse5truefalsetrue23672367falsefalsefalsetruefalseOthernanafalsefalseR16falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseR2rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006441Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundR2iso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>Class R2 Shares</pre>Class R2 Sharesfalsefalsefalsetruefalse2truefalsetrue143143falsefalsefalsetruefalse3truefalsetrue475475falsefalsefalsetruefalse4truefalsetrue831831falsefalsefalsetruefalse5truefalsetrue18331833falsefalsefalsetruefalseOthernanafalsefalseR27falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseR3rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006442Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundR3iso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>Class R3 Shares</pre>Class R3 Sharesfalsefalsefalsetruefalse2truefalsetrue117117falsefalsefalsetruefalse3truefalsetrue397397falsefalsefalsetruefalse4truefalsetrue699699falsefalsefalsetruefalse5truefalsetrue15551555falsefalsefalsetruefalseOthernanafalsefalseR38falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseR4rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006431Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundR4iso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>Class R4 Shares</pre>Class R4 Sharesfalsefalsefalsetruefalse2truefalsetrue9292falsefalsefalsetruefalse3truefalsetrue319319falsefalsefalsetruefalse4truefalsetrue565565falsefalsefalsetruefalse5truefalsetrue12691269falsefalsefalsetruefalseOthernanafalsefalseR458Expense Example MFS Growth Fund (USD $)UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ExpenseExample.No authoritative reference available.falsefalseExpense Example, With Redemption [Table]16false0rr_ExpenseExampleNoRedemptionTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://www.mfs.com/role/ExpenseExampleNoRedemption_S000002419Member column dei_LegalEntityAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div>falsefalse<div style="display:none">~ http://www.mfs.com/role/ExpenseExampleNoRedemption_S000002419Member column dei_LegalEntityAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div>truehttp://www.mfs.com/role/ExpenseExampleNoRedemption_S000002419Memberfalsefalse0116 - Schedule - Expense Example, No Redemption {Transposed}truefalsefalse1falseColumnprimaryElement*3false0rr_ExpenseExampleNoRedemptionByYearColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>Class B Shares assuming no redemption at end of period</pre>falsefalsefalsetruefalse2falsefalsefalse00<pre>Class C Shares assuming no redemption at end of period</pre>falsefalsefalsetruefalseOtherus-types:textBlockItemTypestringYou would pay the following expenses if you did not redeem your shares.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 2 -Subparagraph 1 -Subsection example falsefalseExpense Example, No Redemption, By Year, Column NamefalseUSDfalsefalse$2falseColumnprimaryElement*4false0rr_ExpenseExampleNoRedemptionYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue193193falsefalsefalsetruefalse2truefalsetrue193193falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryYou would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 2 -Subparagraph 1 -Subsection example falsefalseExpense Example, No Redemption, 1 YearfalseUSDfalsefalse$3falseColumnprimaryElement*5false0rr_ExpenseExampleNoRedemptionYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue628628falsefalsefalsetruefalse2truefalsetrue628628falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryYou would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 2 -Subparagraph 1 -Subsection example falsefalseExpense Example, No Redemption, 3 YearsfalseUSDfalsefalse$4falseColumnprimaryElement*6false0rr_ExpenseExampleNoRedemptionYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue10901090falsefalsefalsetruefalse2truefalsetrue10901090falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryYou would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subparagraph f -Subsection instructions falsefalseExpense Example, No Redemption, 5 YearsfalseUSDfalsefalse$5falseColumnprimaryElement*7false0rr_ExpenseExampleNoRedemptionYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue21752175falsefalsefalsetruefalse2truefalsetrue23672367falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryYou would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subparagraph f -Subsection instructions falsefalseExpense Example, No Redemption, 10 YearsfalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseBrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006435Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundBiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>Class B Shares assuming no redemption at end of period</pre>Class B Shares assuming no redemption at end of periodfalsefalsefalsetruefalse2truefalsetrue193193falsefalsefalsetruefalse3truefalsetrue628628falsefalsefalsetruefalse4truefalsetrue10901090falsefalsefalsetruefalse5truefalsetrue21752175falsefalsefalsetruefalseOthernanafalsefalseB2falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseCrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006436Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundCiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>Class C Shares assuming no redemption at end of period</pre>Class C Shares assuming no redemption at end of periodfalsefalsefalsetruefalse2truefalsetrue193193falsefalsefalsetruefalse3truefalsetrue628628falsefalsefalsetruefalse4truefalsetrue10901090falsefalsefalsetruefalse5truefalsetrue23672367falsefalsefalsetruefalseOthernanafalsefalseC52Expense Example, No Redemption MFS Growth Fund (USD $)UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ExpenseExampleNoRedemption.No authoritative reference available.falsefalseExpense Example, No Redemption [Table]17false0rr_PortfolioTurnoverHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Portfolio TurnoverfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 5 -Subsection instructions falsefalsePortfolio Turnover, Heading18false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These transaction costs, which are not reflected in "Annual Fund Operating Expenses" or in the "Example," affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 103% of the average value of its portfolio.</pre>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subsection example falsefalsePortfolio Turnover19false0rr_StrategyHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Principal Investment StrategiesfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseInvestment Strategy, Heading20false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>MFS (Massachusetts Financial Services Company, the fund's investment adviser) normally invests the fund's assets primarily in equity securities. Equity securities include common stocks, preferred stocks, securities convertible into stocks, and depositary receipts for those securities. MFS focuses on investing the fund's assets in the stocks of companies it believes to have above average earnings growth potential compared to other companies (growth companies). MFS may invest the fund's assets in companies of any size. MFS may invest the fund's assets in foreign securities. MFS uses a bottom-up investment approach to buying and selling investments for the fund. Investments are selected primarily based on fundamental analysis of individual issuers and their potential in light of their current financial condition, and market, economic, political, and regulatory conditions. Factors considered may include analysis of an issuer's earnings, cash flows, competitive position, and management ability. Quantitative models that systematically evaluate an issuer's valuation, price and earnings momentum, earnings quality, and other factors may also be considered.</pre>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseInvestment Strategy, Narrative21false0rr_RiskHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Principal RisksfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subsection b falsefalseRisk, Heading22false0rr_RiskNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>As with any mutual fund, the fund may not achieve its objective and/or you could lose money on your investment in the fund. An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. The principal risks of investing in the fund are: Stock Market/Company Risk: Stock markets are volatile and can decline significantly in response to issuer, market, economic, industry, political, regulatory, geopolitical, and other conditions, as well as to investor perceptions of these conditions. The price of an equity security can decrease significantly in response to these conditions, and these conditions can affect a single issuer or type of security, issuers within a broad market sector, industry or geographic region, or the market in general. Growth Company Risk: The stocks of growth companies can be more sensitive to the company's earnings and more volatile than the market in general. Foreign Risk: Exposure to foreign markets through issuers or currencies can involve additional risks relating to market, economic, political, regulatory, geopolitical, or other conditions. These factors can make foreign investments, especially those in emerging markets, more volatile and less liquid than U.S. investments. In addition, foreign markets can react differently to these conditions than the U.S. market. Investment Selection Risk: The MFS analysis of an investment can be incorrect and can lead to an investment focus that results in the fund underperforming other funds with similar investment strategies and/or underperforming the markets in which the fund invests. Counterparty and Third Party Risk: Transactions involving a counterparty or third party other than the issuer of the instrument are subject to the credit risk of the counterparty or third party, and to the counterparty's or third party's ability to perform in accordance with the terms of the transaction. Liquidity Risk: It may not be possible to sell certain investments, types of investments, and/or segments of the market at any particular time or at an acceptable price.</pre>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringNarrative Risk Disclosure. A Fund may, in responding to this Item, describe the types of investors for whom the Fund is intended or the types of investment goals that may be consistent with an investment in the Fund.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph i -Clause instruction -Subsection b falsefalseRisk, Narrative23false0rr_BarChartAndPerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Performance InformationfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart and Performance Table, Heading24false0rr_PerformanceNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>The bar chart and performance table below are intended to provide some indication of the risks of investing in the fund by showing changes in the fund's performance over time and how the fund's performance over time compares with that of a broad measure of market performance. The fund's past performance (before and after taxes) does not necessarily indicate how the fund will perform in the future. Updated performance is available online at mfs.com or by calling 1-800-225-2606.</pre>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalsePerformance, Narrative25false0rr_BarChartNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>The bar chart does not take into account any sales charges (loads) that you may be required to pay upon purchase or redemption of the fund's shares. If these sales charges were included, they would reduce the returns shown.</pre>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringProvide a brief explanation of how the information illustrates the variability of the Fund's returns (e.g., by stating that the information provides some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance). Provide a statement to the effect that the Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph i -Subsection b falsefalseBar Chart, Narrative26false0rr_BarChartHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class A Bar Chart.falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart, Heading27false0rr_BarChartTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://www.mfs.com/role/BarChartData_S000002419Member column dei_LegalEntityAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div>falsefalseBarChart1.jpg<div style="display:none">~ http://www.mfs.com/role/BarChartData_S000002419Member column dei_LegalEntityAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div>falsehttp://www.mfs.com/role/BarChartData_S000002419Memberfalsefalse0117 - Schedule - Annual Total Returnstruefalsefalse1falseColumnperiodPeriod*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseArr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006430Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundAiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*3false0rr_AnnualReturn2001rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.2582-0.2582falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalseAnnual Return 20010rr_AnnualReturn2001truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.2582-0.2582falsefalsefalsetruefalseOthernanafalsefalseAnnual Return 20012falseRowprimaryElement*4false0rr_AnnualReturn2002rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.3543-0.3543falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalseAnnual Return 20020rr_AnnualReturn2002truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.3543-0.3543falsefalsefalsetruefalseOthernanafalsefalseAnnual Return 20023falseRowprimaryElement*5false0rr_AnnualReturn2003rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.31790.3179falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalseAnnual Return 20030rr_AnnualReturn2003truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.31790.3179falsefalsefalsetruefalseOthernanafalsefalseAnnual Return 20034falseRowprimaryElement*6false0rr_AnnualReturn2004rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.13050.1305falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalseAnnual Return 20040rr_AnnualReturn2004truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.13050.1305falsefalsefalsetruefalseOthernanafalsefalseAnnual Return 20045falseRowprimaryElement*7false0rr_AnnualReturn2005rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.08670.0867falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalseAnnual Return 20050rr_AnnualReturn2005truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.08670.0867falsefalsefalsetruefalseOthernanafalsefalseAnnual Return 20056falseRowprimaryElement*8false0rr_AnnualReturn2006rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.07540.0754falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalseAnnual Return 20060rr_AnnualReturn2006truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.07540.0754falsefalsefalsetruefalseOthernanafalsefalseAnnual Return 20067falseRowprimaryElement*9false0rr_AnnualReturn2007rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.20820.2082falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalseAnnual Return 20070rr_AnnualReturn2007truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.20820.2082falsefalsefalsetruefalseOthernanafalsefalseAnnual Return 20078falseRowprimaryElement*10false0rr_AnnualReturn2008rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.3761-0.3761falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalseAnnual Return 20080rr_AnnualReturn2008truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.3761-0.3761falsefalsefalsetruefalseOthernanafalsefalseAnnual Return 20089falseRowprimaryElement*11false0rr_AnnualReturn2009rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.38190.3819falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalseAnnual Return 20090rr_AnnualReturn2009truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.38190.3819falsefalsefalsetruefalseOthernanafalsefalseAnnual Return 200910falseRowprimaryElement*12false0rr_AnnualReturn2010rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.15650.1565falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalseAnnual Return 20100rr_AnnualReturn2010truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.15650.1565falsefalsefalsetruefalseOthernanafalsefalseAnnual Return 2010110Annual Total Returns UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to BarChartData.No authoritative reference available.falsefalseBar Chart [Table]28false0rr_BarChartClosingTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>During the period(s) shown in the bar chart, the highest quarterly return was 25.31% (for the calendar quarter ended December 31, 2001) and the lowest quarterly return was (31.50)% (for the calendar quarter ended September 30, 2001).</pre>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalseBar Chart, Closing29false0rr_PerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Performance Table.falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit c -Subsection b falsefalsePerformance Table, Heading30false0rr_PerformanceTableNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<pre>After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Your actual after-tax returns will depend on your own tax situation, and may differ from those shown. The after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. The after-tax returns are shown for only one of the fund's classes of shares, and after-tax returns for the fund's other classes of shares will vary from the returns shown.</pre>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringIf the Fund has annual returns for at least one calendar year, provide a table showing the Fund's (A) average annual total return; (B) average annual total return (after taxes on distributions); and (C) average annual total return (after taxes on distributions and redemption). A Money Market Fund should show only the returns described in clause (A) of the preceding sentence. All returns should be shown for 1-, 5-, and 10- calendar year periods ending on the date of the most recently completed calendar year (or for the life of the Fund, if shorter), but only for periods subsequent to the effective date of the Fund's registration statement. The table also shouldshow the returns of an appropriate broadbased securities market index as defined in Instruction 5 to Item 22(b)(7) for the same periods. A Fund that has been in existence for more than 10 years also may include returns for the life of the Fund. A Money Market Fund may provide the Fund's 7-day yield ending on the date of the most recent calendar year or disclose a toll-free (or collect) telephone number that investors can use to obtain the Fund's current 7-day yield. For a Fund (other than a Money Market Fund or a Fund described in General Instruction C.3.(d)(iii)), provide the information in the following table with the specified captions AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, _____). For a Fund that provides annual total returns for only one calendar year or for a Fund that does not include the bar chart because it does not have annual returns for a full calendar year, modify, as appropriate, the narrative explanation required by paragraph (c)(2)(i) (e.g., by stating that the information gives some indication of the risks of an investment in the Fund by comparing the Fund's performance with a broad measure of market performance).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iv -Subsection b falsefalsePerformance Table, Narrative31false0rr_AverageAnnualReturnCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00Average Annual Total Returns (for the Periods Ended December 31, 2010)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 5 -Subsection b falsefalseAverage Annual Returns, Caption32false0rr_PerformanceTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://www.mfs.com/role/PerformanceTableData_S000002419Member column dei_LegalEntityAxis compact * column rr_PerformanceMeasureAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div>falsefalse<div style="display:none">~ http://www.mfs.com/role/PerformanceTableData_S000002419Member column dei_LegalEntityAxis compact * column rr_PerformanceMeasureAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div>truehttp://www.mfs.com/role/PerformanceTableData_S000002419Memberfalsefalse0118 - Schedule - Average Annual Total Returns {Transposed}truefalsefalse1falseColumnprimaryElement*3false0rr_AverageAnnualReturnLabelrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00A Shares Returns Before Taxesfalsefalsefalsetruefalse2falsetruefalse00A Shares Returns After Taxes on Distributionsfalsefalsefalsetruefalse3falsetruefalse00A Shares Returns After Taxes on Distributions and Sale of Fund Sharesfalsefalsefalsetruefalse4falsetruefalse00B Shares Returns Before Taxesfalsefalsefalsetruefalse5falsetruefalse00C Shares Returns Before Taxesfalsefalsefalsetruefalse6falsetruefalse00I Shares Returns Before Taxesfalsefalsefalsetruefalse7falsetruefalse00R1 Shares Returns Before Taxesfalsefalsefalsetruefalse8falsetruefalse00R2 Shares Returns Before Taxesfalsefalsefalsetruefalse9falsetruefalse00R3 Shares Returns Before Taxesfalsefalsefalsetruefalse10falsetruefalse00R4 Shares Returns Before Taxesfalsefalsefalsetruefalse11falsetruefalse00Russell 1000 Growth Index (Reflects no deduction for fees, expenses or taxes)falsefalsefalsetruefalseOtherxbrli:stringItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalseAverage Annual Returns, LabelfalseUSDfalsefalse$2falseColumnprimaryElement*4false0rr_AverageAnnualReturnYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.09000.0900falsefalsefalsetruefalse2truetruetrue0.09000.0900falsefalsefalsetruefalse3truetruetrue0.05850.0585falsefalsefalsetruefalse4truetruetrue0.10820.1082falsefalsefalsetruefalse5truetruetrue0.13820.1382falsefalsefalsetruefalse6truetruetrue0.15960.1596falsefalsefalsetruefalse7truetruetrue0.14830.1483falsefalsefalsetruefalse8truetruetrue0.15410.1541falsefalsefalsetruefalse9truetruetrue0.15700.1570falsefalsefalsetruefalse10truetruetrue0.15970.1597falsefalsefalsetruefalse11truetruetrue0.16710.1671falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalseAverage Annual Returns, 1 YearfalseUSDfalsefalse$3falseColumnprimaryElement*5false0rr_AverageAnnualReturnYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.04080.0408falsefalsefalsetruefalse2truetruetrue0.03860.0386falsefalsefalsetruefalse3truetruetrue0.03500.0350falsefalsefalsetruefalse4truetruetrue0.04190.0419falsefalsefalsetruefalse5truetruetrue0.04530.0453falsefalsefalsetruefalse6truetruetrue0.05590.0559falsefalsefalsetruefalse7truetruetrue0.04500.0450falsefalsefalsetruefalse8truetruetrue0.05000.0500falsefalsefalsetruefalse9truetruetrue0.05260.0526falsefalsefalsetruefalse10truetruetrue0.05550.0555falsefalsefalsetruefalse11truetruetrue0.03750.0375falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalseAverage Annual Returns, 5 YearsfalseUSDfalsefalse$4falseColumnprimaryElement*6false0rr_AverageAnnualReturnYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue-0.0054-0.0054falsefalsefalsetruefalse2truetruetrue-0.0065-0.0065falsefalsefalsetruefalse3truetruetrue-0.0046-0.0046falsefalsefalsetruefalse4truetruetrue-0.0055-0.0055falsefalsefalsetruefalse5truetruetrue-0.0070-0.0070falsefalsefalsetruefalse6truetruetrue0.00300.0030falsefalsefalsetruefalse7truetruetrue-0.0081-0.0081falsefalsefalsetruefalse8truetruetrue-0.0034-0.0034falsefalsefalsetruefalse9truetruetrue-0.0005-0.0005falsefalsefalsetruefalse10truetruetrue0.00240.0024falsefalsefalsetruefalse11truetruetrue0.00020.0002falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalseAverage Annual Returns, 10 YearsfalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMembertruefalseBefore Taxesrr_PerformanceMeasureAxisrr_PerformanceMeasureDomainrr_PerformanceMeasureAxisexplicitMemberfalsefalseArr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006430Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundBefore TaxesAiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00A Shares Returns Before TaxesA Shares Returns Before Taxesfalsefalsefalsetruefalse2truetruetrue0.09000.0900falsefalsefalsetruefalse3truetruetrue0.04080.0408falsefalsefalsetruefalse4truetruetrue-0.0054-0.0054falsefalsefalsetruefalseOthernanafalsefalseA2falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMembertruefalseBefore Taxesrr_PerformanceMeasureAxisrr_PerformanceMeasureDomainrr_PerformanceMeasureAxisexplicitMemberfalsefalseBrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006435Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundBefore TaxesBiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00B Shares Returns Before TaxesB Shares Returns Before Taxesfalsefalsefalsetruefalse2truetruetrue0.10820.1082falsefalsefalsetruefalse3truetruetrue0.04190.0419falsefalsefalsetruefalse4truetruetrue-0.0055-0.0055falsefalsefalsetruefalseOthernanafalsefalseB3falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMembertruefalseBefore Taxesrr_PerformanceMeasureAxisrr_PerformanceMeasureDomainrr_PerformanceMeasureAxisexplicitMemberfalsefalseCrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006436Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundBefore TaxesCiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00C Shares Returns Before TaxesC Shares Returns Before Taxesfalsefalsefalsetruefalse2truetruetrue0.13820.1382falsefalsefalsetruefalse3truetruetrue0.04530.0453falsefalsefalsetruefalse4truetruetrue-0.0070-0.0070falsefalsefalsetruefalseOthernanafalsefalseC4falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMembertruefalseBefore Taxesrr_PerformanceMeasureAxisrr_PerformanceMeasureDomainrr_PerformanceMeasureAxisexplicitMemberfalsefalseIrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006437Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundBefore TaxesIiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00I Shares Returns Before TaxesI Shares Returns Before Taxesfalsefalsefalsetruefalse2truetruetrue0.15960.1596falsefalsefalsetruefalse3truetruetrue0.05590.0559falsefalsefalsetruefalse4truetruetrue0.00300.0030falsefalsefalsetruefalseOthernanafalsefalseI5falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMembertruefalseBefore Taxesrr_PerformanceMeasureAxisrr_PerformanceMeasureDomainrr_PerformanceMeasureAxisexplicitMemberfalsefalseR1rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006439Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundBefore TaxesR1iso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00R1 Shares Returns Before TaxesR1 Shares Returns Before Taxesfalsefalsefalsetruefalse2truetruetrue0.14830.1483falsefalsefalsetruefalse3truetruetrue0.04500.0450falsefalsefalsetruefalse4truetruetrue-0.0081-0.0081falsefalsefalsetruefalseOthernanafalsefalseR16falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMembertruefalseBefore Taxesrr_PerformanceMeasureAxisrr_PerformanceMeasureDomainrr_PerformanceMeasureAxisexplicitMemberfalsefalseR2rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006441Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundBefore TaxesR2iso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00R2 Shares Returns Before TaxesR2 Shares Returns Before Taxesfalsefalsefalsetruefalse2truetruetrue0.15410.1541falsefalsefalsetruefalse3truetruetrue0.05000.0500falsefalsefalsetruefalse4truetruetrue-0.0034-0.0034falsefalsefalsetruefalseOthernanafalsefalseR27falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMembertruefalseBefore Taxesrr_PerformanceMeasureAxisrr_PerformanceMeasureDomainrr_PerformanceMeasureAxisexplicitMemberfalsefalseR3rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006442Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundBefore TaxesR3iso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00R3 Shares Returns Before TaxesR3 Shares Returns Before Taxesfalsefalsefalsetruefalse2truetruetrue0.15700.1570falsefalsefalsetruefalse3truetruetrue0.05260.0526falsefalsefalsetruefalse4truetruetrue-0.0005-0.0005falsefalsefalsetruefalseOthernanafalsefalseR38falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMembertruefalseBefore Taxesrr_PerformanceMeasureAxisrr_PerformanceMeasureDomainrr_PerformanceMeasureAxisexplicitMemberfalsefalseR4rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006431Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundBefore TaxesR4iso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00R4 Shares Returns Before TaxesR4 Shares Returns Before Taxesfalsefalsefalsetruefalse2truetruetrue0.15970.1597falsefalsefalsetruefalse3truetruetrue0.05550.0555falsefalsefalsetruefalse4truetruetrue0.00240.0024falsefalsefalsetruefalseOthernanafalsefalseR49falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseAfter Taxes on Distributionsrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldirr_AfterTaxesOnDistributionsMemberrr_PerformanceMeasureAxisexplicitMemberfalsefalseArr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006430Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundAfter Taxes on DistributionsAStandard00truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00A Shares Returns After Taxes on DistributionsA Shares Returns After Taxes on Distributionsfalsefalsefalsetruefalse2truetruetrue0.09000.0900falsefalsefalsetruefalse3truetruetrue0.03860.0386falsefalsefalsetruefalse4truetruetrue-0.0065-0.0065falsefalsefalsetruefalseOthernanafalsefalseAfter Taxes on Distributions A10falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseAfter Taxes on Distributions and Salesrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldirr_AfterTaxesOnDistributionsAndSalesMemberrr_PerformanceMeasureAxisexplicitMemberfalsefalseArr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_C000006430Memberrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundAfter Taxes on Distributions and SalesAStandard00truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00A Shares Returns After Taxes on Distributions and Sale of Fund SharesA Shares Returns After Taxes on Distributions and Sale of Fund Sharesfalsefalsefalsetruefalse2truetruetrue0.05850.0585falsefalsefalsetruefalse3truetruetrue0.03500.0350falsefalsefalsetruefalse4truetruetrue-0.0046-0.0046falsefalsefalsetruefalseOthernanafalsefalseAfter Taxes on Distributions and Sales A11falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2011-03-30T00:00:002011-03-30T00:00:00falsefalseMFS Growth Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_S000002419Memberdei_LegalEntityAxisexplicitMemberfalsefalseRussell 1000 Growth Indexrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldick0000798250_RRINDEX00001Memberrr_PerformanceMeasureAxisexplicitMembertruefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberMFS Growth FundRussell 1000 Growth IndexShare ClassesStandard00truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00Russell 1000 Growth Index (Reflects no deduction for fees, expenses or taxes)Russell 1000 Growth Index (Reflects no deduction for fees, expenses or taxes)falsefalsefalsetruefalse2truetruetrue0.16710.1671falsefalsefalsetruefalse3truetruetrue0.03750.0375falsefalsefalsetruefalse4truetruetrue0.00020.0002falsefalsefalsetruefalseOthernanafalsefalseRussell 1000 Growth Index411Average Annual Total Returns MFS Growth FundUnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to PerformanceTableData.No authoritative reference available.falsefalsePerformance [Table]131Risk/Return Summary (MFS Growth Fund) (MFS Growth Fund (Prospectus Summary), MFS Growth Fund)UnKnownUnKnownUnKnownUnKnownfalsetrue