Risk/Return Detail Data - FidelitySeriesLargeCapStockFund-PRO - USD ($)			12 Months Ended											60 Months Ended	120 Months Ended
		Aug. 29, 2025	Aug. 29, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Aug. 29, 2025	Aug. 29, 2025
FidelityFund-RetailPRO | Fidelity Fund | Fidelity Fund
Prospectus Line Items
Management Fees (as a percentage of Assets)		0.42%
Distribution and Service (12b-1) Fees		0.00%
Other Expenses (as a percentage of Assets):		0.00%
Expenses (as a percentage of Assets)		0.42%
Expense Example, with Redemption, 1 Year		$ 43
Expense Example, with Redemption, 3 Years		135
Expense Example, with Redemption, 5 Years		235
Expense Example, with Redemption, 10 Years		$ 530
Average Annual Return, Label [Optional Text]			Return Before Taxes
Average Annual Return, Percent			27.13%											15.75%	13.43%
Annual Return [Percent]				27.13%	30.92%	(25.87%)	33.21%	26.43%	33.48%	(5.24%)	23.82%	4.82%	3.35%
FidelityFund-RetailPRO | Fidelity Fund
Prospectus Line Items
Risk/Return [Heading]		Fund Summary Fund /Class: Fidelity® Fund /Fidelity® Fund
Objective [Heading]		Investment Objective
Objective, Primary [Text Block]		Fidelity® Fund seeks long-term capital growth.
Expense Heading [Optional Text]		Fee Table
Expense Narrative [Text Block]		The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text]		Shareholder fees
Shareholder Fee, Other		$ 0
Operating Expenses Caption [Optional Text]		Annual Operating Expenses
Portfolio Turnover [Heading]		Portfolio Turnover
Portfolio Turnover [Text Block]		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 fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 31 % of the average value of its portfolio.
Portfolio Turnover, Rate		31.00%
Expense Example Narrative [Text Block]		This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:
Strategy [Heading]		Principal Investment Strategies
Strategy Narrative [Text Block]		Normally investing primarily in common stocks. Potentially investing a portion of assets in bonds, including lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). Investing in domestic and foreign issuers. Investing in either "growth" stocks or "value" stocks or both. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.
Bar Chart and Performance Table [Heading]		Performance
Performance Narrative [Text Block]		The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index over various periods of time. The index description appears in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.
Performance Information Illustrates Variability of Returns [Text]		The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index over various periods of time.
Performance Availability Website Address [Text]		www.fidelity.com
Performance Past Does Not Indicate Future [Text]		Past performance (before and after taxes) is not an indication of future performance.
Bar Chart [Heading]		Year-by-Year Returns
Year to Date Return, Label [Optional Text]		Year-to-Date Return
Bar Chart, Year to Date Return, Date		Jun. 30, 2025
Bar Chart, Year to Date Return		6.90%
Highest Quarterly Return, Label [Optional Text]		Highest Quarter Return
Highest Quarterly Return, Date		Jun. 30, 2020
Highest Quarterly Return		23.43%
Lowest Quarterly Return, Label [Optional Text]		Lowest Quarter Return
Lowest Quarterly Return, Date		Jun. 30, 2022
Lowest Quarterly Return		(18.60%)
Performance Table Heading		Average Annual Returns
Performance Table Uses Highest Federal Rate		After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.
Performance Table Not Relevant to Tax Deferred		The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).
Performance Table Explanation after Tax Higher		Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.
Performance Table Narrative		After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.
FidelityFund-RetailPRO | Fidelity Fund | After Taxes on Distributions | Fidelity Fund
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Return After Taxes on Distributions
Average Annual Return, Percent			27.13%											15.17%	12.20%
FidelityFund-RetailPRO | Fidelity Fund | After Taxes on Distributions and Sales | Fidelity Fund
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Return After Taxes on Distributions and Sale of Fund Shares
Average Annual Return, Percent			16.06%											12.60%	10.71%
FidelityFund-RetailPRO | Fidelity Fund | SP001
Prospectus Line Items
Average Annual Return, Label [Optional Text]			S&P 500® Index
Average Annual Return, Percent			25.02%											14.53%	13.10%
FidelitySeriesLargeCapStockFund-PRO | Fidelity Series Large Cap Stock Fund | Fidelity Series Large Cap Stock Fund
Prospectus Line Items
Management Fees (as a percentage of Assets)		0.00%
Distribution and Service (12b-1) Fees		0.00%
Other Expenses (as a percentage of Assets):		0.00%
Expenses (as a percentage of Assets)		0.00%
Expense Example, with Redemption, 1 Year		$ 0
Expense Example, with Redemption, 3 Years		0
Expense Example, with Redemption, 5 Years		0
Expense Example, with Redemption, 10 Years		$ 0
Average Annual Return, Label [Optional Text]			Return Before Taxes
Average Annual Return, Percent			27.39%											15.46%	12.57%
Annual Return [Percent]				27.39%	24.77%	(7.24%)	26.44%	10.07%	31.55%	(8.84%)	17.36%	15.96%	(2.38%)
FidelitySeriesLargeCapStockFund-PRO | Fidelity Series Large Cap Stock Fund
Prospectus Line Items
Risk/Return [Heading]		Fund Summary Fund: Fidelity® Series Large Cap Stock Fund
Objective [Heading]		Investment Objective
Objective, Primary [Text Block]		Fidelity® Series Large Cap Stock Fund seeks long-term growth of capital.
Expense Heading [Optional Text]		Fee Table
Expense Narrative [Text Block]		The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund.
Shareholder Fees Caption [Optional Text]		Shareholder fees
Shareholder Fee, Other		$ 0
Operating Expenses Caption [Optional Text]		Annual Operating Expenses
Portfolio Turnover [Heading]		Portfolio Turnover
Portfolio Turnover [Text Block]		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 fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 17 % of the average value of its portfolio.
Portfolio Turnover, Rate		17.00%
Expense Example Narrative [Text Block]		This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:
Strategy [Heading]		Principal Investment Strategies
Strategy Narrative [Text Block]		Normally investing at least 80% of assets in common stocks of companies with large market capitalizations. The Adviser generally defines large market capitalization companies as those whose market capitalization is similar to the market capitalization of companies in the Russell 1000 ® Index or the S&P 500 ® Index. Common stocks (including depositary receipts evidencing ownership of common stock) are a type of equity security that represents an ownership interest in an issuer. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Investing in domestic and foreign issuers. Investing in either "growth" stocks or "value" stocks or both. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.
Bar Chart and Performance Table [Heading]		Performance
Performance Narrative [Text Block]		The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index over various periods of time. The index description appears in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. The performance shown does not reflect the impact of any fees paid at the fee-based account or plan level, if applicable. Prior to September 29, 2018, the fund was named Fidelity ® Series Growth & Income Fund, and the fund operated under certain different investment policies and compared its performance to a different additional index. The fund's historical performance may not represent its current investment policies. Visit www.fidelity.com for more recent performance information.
Performance Information Illustrates Variability of Returns [Text]		The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index over various periods of time.
Performance Availability Website Address [Text]		www.fidelity.com
Performance Past Does Not Indicate Future [Text]		Past performance (before and after taxes) is not an indication of future performance.
Bar Chart [Heading]		Year-by-Year Returns
Year to Date Return, Label [Optional Text]		Year-to-Date Return
Bar Chart, Year to Date Return, Date		Jun. 30, 2025
Bar Chart, Year to Date Return		12.81%
Highest Quarterly Return, Label [Optional Text]		Highest Quarter Return
Highest Quarterly Return, Date		Dec. 31, 2020
Highest Quarterly Return		18.85%
Lowest Quarterly Return, Label [Optional Text]		Lowest Quarter Return
Lowest Quarterly Return, Date		Mar. 31, 2020
Lowest Quarterly Return		(24.26%)
Performance Table Heading		Average Annual Returns
Performance Table Uses Highest Federal Rate		After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.
Performance Table Not Relevant to Tax Deferred		The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).
Performance Table Explanation after Tax Higher		Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.
Performance Table Narrative		After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.
FidelitySeriesLargeCapStockFund-PRO | Fidelity Series Large Cap Stock Fund | After Taxes on Distributions | Fidelity Series Large Cap Stock Fund
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Return After Taxes on Distributions
Average Annual Return, Percent			24.92%											13.49%	10.76%
FidelitySeriesLargeCapStockFund-PRO | Fidelity Series Large Cap Stock Fund | After Taxes on Distributions and Sales | Fidelity Series Large Cap Stock Fund
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Return After Taxes on Distributions and Sale of Fund Shares
Average Annual Return, Percent			17.68%											11.92%	9.79%
FidelitySeriesLargeCapStockFund-PRO | Fidelity Series Large Cap Stock Fund | SP001
Prospectus Line Items
Average Annual Return, Label [Optional Text]			S&P 500® Index
Average Annual Return, Percent			25.02%											14.53%	13.10%
FidelityGrowthDiscoveryFund-RetailPRO | Fidelity Growth Discovery Fund | Fidelity Growth Discovery Fund
Prospectus Line Items
Management Fees (as a percentage of Assets)	[1]	0.61%
Distribution and Service (12b-1) Fees		0.00%
Other Expenses (as a percentage of Assets):		0.01%
Expenses (as a percentage of Assets)		0.62%
Expense Example, with Redemption, 1 Year		$ 63
Expense Example, with Redemption, 3 Years		199
Expense Example, with Redemption, 5 Years		346
Expense Example, with Redemption, 10 Years		$ 774
Average Annual Return, Label [Optional Text]			Return Before Taxes
Average Annual Return, Percent			30.10%											18.67%	16.40%
Annual Return [Percent]				30.10%	35.65%	(24.44%)	23.00%	43.50%	33.79%	(0.27%)	34.70%	0.68%	7.16%
FidelityGrowthDiscoveryFund-RetailPRO | Fidelity Growth Discovery Fund
Prospectus Line Items
Risk/Return [Heading]		Fund Summary Fund /Class: Fidelity® Growth Discovery Fund /Fidelity® Growth Discovery Fund
Objective [Heading]		Investment Objective
Objective, Primary [Text Block]		Fidelity® Growth Discovery Fund seeks capital appreciation.
Expense Heading [Optional Text]		Fee Table
Expense Narrative [Text Block]		The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text]		Shareholder fees
Shareholder Fee, Other		$ 0
Operating Expenses Caption [Optional Text]		Annual Operating Expenses
Portfolio Turnover [Heading]		Portfolio Turnover
Portfolio Turnover [Text Block]		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 fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 60 % of the average value of its portfolio.
Portfolio Turnover, Rate		60.00%
Expense Example Narrative [Text Block]		This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:
Strategy [Heading]		Principal Investment Strategies
Strategy Narrative [Text Block]		Normally investing primarily in common stocks. Investing in companies that Fidelity Management & Research Company LLC (FMR) believes have above-average growth potential (stocks of these companies are often called "growth" stocks). Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments. Effective December 11, 2025, normally investing at least 80% of assets in securities of growth companies. Growth companies are companies the Adviser believes have above average growth potential. The Adviser considers a number of factors in determining a company's growth potential, such as whether the company is included in a third-party growth benchmark or classified as a growth company by a third-party vendor, if the company's projected earnings per share growth, sales growth per share or free cash flow growth or its trailing earnings per share growth is above the equity market median, if the company's research and development expenses exceed sales, general and administrative expenses, or if the company is raising capital to grow, fund or expand its business. A company's growth potential can be determined under any of these factors. Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.
Bar Chart and Performance Table [Heading]		Performance
Performance Narrative [Text Block]		The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.
Performance Information Illustrates Variability of Returns [Text]		The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.
Performance Availability Website Address [Text]		www.fidelity.com
Performance Past Does Not Indicate Future [Text]		Past performance (before and after taxes) is not an indication of future performance.
Bar Chart [Heading]		Year-by-Year Returns
Year to Date Return, Label [Optional Text]		Year-to-Date Return
Bar Chart, Year to Date Return, Date		Jun. 30, 2025
Bar Chart, Year to Date Return		6.25%
Highest Quarterly Return, Label [Optional Text]		Highest Quarter Return
Highest Quarterly Return, Date		Jun. 30, 2020
Highest Quarterly Return		31.42%
Lowest Quarterly Return, Label [Optional Text]		Lowest Quarter Return
Lowest Quarterly Return, Date		Jun. 30, 2022
Lowest Quarterly Return		(18.01%)
Performance Table Heading		Average Annual Returns
Performance Table Uses Highest Federal Rate		After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.
Performance Table Not Relevant to Tax Deferred		The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).
Performance Table Explanation after Tax Higher		Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.
Performance Table Narrative		After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.
FidelityGrowthDiscoveryFund-RetailPRO | Fidelity Growth Discovery Fund | After Taxes on Distributions | Fidelity Growth Discovery Fund
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Return After Taxes on Distributions
Average Annual Return, Percent			26.30%											16.28%	14.83%
FidelityGrowthDiscoveryFund-RetailPRO | Fidelity Growth Discovery Fund | After Taxes on Distributions and Sales | Fidelity Growth Discovery Fund
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Return After Taxes on Distributions and Sale of Fund Shares
Average Annual Return, Percent			20.23%											14.60%	13.47%
FidelityGrowthDiscoveryFund-RetailPRO | Fidelity Growth Discovery Fund | RS007
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Russell 3000® Growth Index
Average Annual Return, Percent			32.46%											18.25%	16.22%
FidelityGrowthDiscoveryFund-RetailPRO | Fidelity Growth Discovery Fund | RS003
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Russell 3000® Index
Average Annual Return, Percent			23.81%											13.86%	12.55%
FidelityMegaCapStockFund-RetailPRO | Fidelity Mega Cap Stock Fund | Fidelity Mega Cap Stock Fund
Prospectus Line Items
Management Fees (as a percentage of Assets)		0.57%
Distribution and Service (12b-1) Fees		0.00%
Other Expenses (as a percentage of Assets):		0.01%
Expenses (as a percentage of Assets)		0.58%
Expense Example, with Redemption, 1 Year		$ 59
Expense Example, with Redemption, 3 Years		186
Expense Example, with Redemption, 5 Years		324
Expense Example, with Redemption, 10 Years		$ 726
Average Annual Return, Label [Optional Text]			Return Before Taxes
Average Annual Return, Percent			25.95%											15.64%	12.75%
Annual Return [Percent]				25.95%	26.51%	(8.98%)	26.24%	12.96%	31.14%	(7.23%)	17.77%	13.63%	(1.43%)
FidelityMegaCapStockFund-RetailPRO | Fidelity Mega Cap Stock Fund
Prospectus Line Items
Risk/Return [Heading]		Fund Summary Fund /Class: Fidelity® Mega Cap Stock Fund /Fidelity® Mega Cap Stock Fund
Objective [Heading]		Investment Objective
Objective, Primary [Text Block]		Fidelity® Mega Cap Stock Fund seeks high total return through a combination of current income and capital appreciation.
Expense Heading [Optional Text]		Fee Table
Expense Narrative [Text Block]		The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text]		Shareholder fees
Shareholder Fee, Other		$ 0
Operating Expenses Caption [Optional Text]		Annual Operating Expenses
Portfolio Turnover [Heading]		Portfolio Turnover
Portfolio Turnover [Text Block]		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 fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 15 % of the average value of its portfolio.
Portfolio Turnover, Rate		15.00%
Expense Example Narrative [Text Block]		This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:
Strategy [Heading]		Principal Investment Strategies
Strategy Narrative [Text Block]		Normally investing at least 80% of assets in common stocks of companies with mega market capitalizations. The Adviser generally defines mega market capitalization companies as those whose market capitalization is similar to the market capitalization of companies in the Russell Top 200 ® Index or the S&P 100 ® Index. Common stocks (including depositary receipts evidencing ownership of common stock) are a type of equity security that represents an ownership interest in an issuer. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Investing in domestic and foreign issuers. Investing in either "growth" stocks or "value" stocks or both. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.
Bar Chart and Performance Table [Heading]		Performance
Performance Narrative [Text Block]		The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.
Performance Information Illustrates Variability of Returns [Text]		The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.
Performance Availability Website Address [Text]		www.fidelity.com
Performance Past Does Not Indicate Future [Text]		Past performance (before and after taxes) is not an indication of future performance.
Bar Chart [Heading]		Year-by-Year Returns
Year to Date Return, Label [Optional Text]		Year-to-Date Return
Bar Chart, Year to Date Return, Date		Jun. 30, 2025
Bar Chart, Year to Date Return		12.09%
Highest Quarterly Return, Label [Optional Text]		Highest Quarter Return
Highest Quarterly Return, Date		Dec. 31, 2020
Highest Quarterly Return		18.88%
Lowest Quarterly Return, Label [Optional Text]		Lowest Quarter Return
Lowest Quarterly Return, Date		Mar. 31, 2020
Lowest Quarterly Return		(22.95%)
Performance Table Heading		Average Annual Returns
Performance Table Uses Highest Federal Rate		After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.
Performance Table Not Relevant to Tax Deferred		The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).
Performance Table Explanation after Tax Higher		Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.
Performance Table Narrative		After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.
FidelityMegaCapStockFund-RetailPRO | Fidelity Mega Cap Stock Fund | After Taxes on Distributions | Fidelity Mega Cap Stock Fund
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Return After Taxes on Distributions
Average Annual Return, Percent			25.12%											14.30%	10.72%
FidelityMegaCapStockFund-RetailPRO | Fidelity Mega Cap Stock Fund | After Taxes on Distributions and Sales | Fidelity Mega Cap Stock Fund
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Return After Taxes on Distributions and Sale of Fund Shares
Average Annual Return, Percent			15.90%											12.15%	9.74%
FidelityMegaCapStockFund-RetailPRO | Fidelity Mega Cap Stock Fund | SP001
Prospectus Line Items
Average Annual Return, Label [Optional Text]			S&P 500® Index
Average Annual Return, Percent			25.02%											14.53%	13.10%
FidelityMegaCapStockFund-RetailPRO | Fidelity Mega Cap Stock Fund | RS009
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Russell Top 200® Index
Average Annual Return, Percent			27.44%											15.75%	14.03%
FidelityMegaCapStockFund-AMCIZPRO | Fidelity Mega Cap Stock Fund | Fidelity Advisor Mega Cap Stock Fund - Class A
Prospectus Line Items
Maximum Cumulative Sales Charge (as a percentage of Offering Price)		5.75%
Maximum Deferred Sales Charge (as a percentage)	[2]	0.00%
Management Fees (as a percentage of Assets)		0.60%
Distribution and Service (12b-1) Fees		0.25%
Other Expenses (as a percentage of Assets):		0.01%
Expenses (as a percentage of Assets)		0.86%
Expense Example, with Redemption, 1 Year		$ 658
Expense Example, with Redemption, 3 Years		834
Expense Example, with Redemption, 5 Years		1,024
Expense Example, with Redemption, 10 Years		1,575
Expense Example, No Redemption, 1 Year		658
Expense Example, No Redemption, 3 Years		834
Expense Example, No Redemption, 5 Years		1,024
Expense Example, No Redemption, 10 Years		$ 1,575
Average Annual Return, Label [Optional Text]			Return Before Taxes
Average Annual Return, Percent			18.37%											13.95%	11.77%
Annual Return [Percent]				25.60%	26.18%	(9.27%)	25.94%	12.58%	30.81%	(7.47%)	17.49%	13.33%	(1.74%)
FidelityMegaCapStockFund-AMCIZPRO | Fidelity Mega Cap Stock Fund | Fidelity Advisor Mega Cap Stock Fund - Class M
Prospectus Line Items
Maximum Cumulative Sales Charge (as a percentage of Offering Price)		3.50%
Maximum Deferred Sales Charge (as a percentage)	[2]	0.00%
Management Fees (as a percentage of Assets)		0.60%
Distribution and Service (12b-1) Fees		0.50%
Other Expenses (as a percentage of Assets):		0.01%
Expenses (as a percentage of Assets)		1.11%
Expense Example, with Redemption, 1 Year		$ 459
Expense Example, with Redemption, 3 Years		691
Expense Example, with Redemption, 5 Years		940
Expense Example, with Redemption, 10 Years		1,654
Expense Example, No Redemption, 1 Year		459
Expense Example, No Redemption, 3 Years		691
Expense Example, No Redemption, 5 Years		940
Expense Example, No Redemption, 10 Years		$ 1,654
Average Annual Return, Label [Optional Text]			Return Before Taxes
Average Annual Return, Percent			20.95%											14.20%	11.75%
FidelityMegaCapStockFund-AMCIZPRO | Fidelity Mega Cap Stock Fund | Fidelity Advisor Mega Cap Stock Fund - Class C
Prospectus Line Items
Maximum Cumulative Sales Charge (as a percentage of Offering Price)		0.00%
Maximum Deferred Sales Charge (as a percentage)	[3]	1.00%
Management Fees (as a percentage of Assets)		0.62%
Distribution and Service (12b-1) Fees		1.00%
Other Expenses (as a percentage of Assets):		0.02%
Expenses (as a percentage of Assets)		1.64%
Expenses Deferred Charges [Text Block]		On Class C shares redeemed less than one year after purchase.
Expense Example, with Redemption, 1 Year		$ 267
Expense Example, with Redemption, 3 Years		517
Expense Example, with Redemption, 5 Years		892
Expense Example, with Redemption, 10 Years		1,735
Expense Example, No Redemption, 1 Year		167
Expense Example, No Redemption, 3 Years		517
Expense Example, No Redemption, 5 Years		892
Expense Example, No Redemption, 10 Years		$ 1,735
Average Annual Return, Label [Optional Text]			Return Before Taxes
Average Annual Return, Percent			23.65%											14.42%	11.76%
FidelityMegaCapStockFund-AMCIZPRO | Fidelity Mega Cap Stock Fund | Fidelity Advisor Mega Cap Stock Fund - Class I
Prospectus Line Items
Maximum Cumulative Sales Charge (as a percentage of Offering Price)		0.00%
Maximum Deferred Sales Charge (as a percentage)		0.00%
Management Fees (as a percentage of Assets)		0.58%
Distribution and Service (12b-1) Fees		0.00%
Other Expenses (as a percentage of Assets):		0.01%
Expenses (as a percentage of Assets)		0.59%
Expense Example, with Redemption, 1 Year		$ 60
Expense Example, with Redemption, 3 Years		189
Expense Example, with Redemption, 5 Years		329
Expense Example, with Redemption, 10 Years		738
Expense Example, No Redemption, 1 Year		60
Expense Example, No Redemption, 3 Years		189
Expense Example, No Redemption, 5 Years		329
Expense Example, No Redemption, 10 Years		$ 738
Average Annual Return, Label [Optional Text]			Return Before Taxes
Average Annual Return, Percent			25.97%											15.62%	12.74%
FidelityMegaCapStockFund-AMCIZPRO | Fidelity Mega Cap Stock Fund | Fidelity Advisor Mega Cap Stock Fund - Class Z
Prospectus Line Items
Maximum Cumulative Sales Charge (as a percentage of Offering Price)		0.00%
Maximum Deferred Sales Charge (as a percentage)		0.00%
Management Fees (as a percentage of Assets)		0.46%
Distribution and Service (12b-1) Fees		0.00%
Other Expenses (as a percentage of Assets):		0.01%
Expenses (as a percentage of Assets)		0.47%
Expense Example, with Redemption, 1 Year		$ 48
Expense Example, with Redemption, 3 Years		151
Expense Example, with Redemption, 5 Years		263
Expense Example, with Redemption, 10 Years		591
Expense Example, No Redemption, 1 Year		48
Expense Example, No Redemption, 3 Years		151
Expense Example, No Redemption, 5 Years		263
Expense Example, No Redemption, 10 Years		$ 591
Average Annual Return, Label [Optional Text]			Return Before Taxes
Average Annual Return, Percent			26.10%											15.76%	12.89%
FidelityMegaCapStockFund-AMCIZPRO | Fidelity Mega Cap Stock Fund
Prospectus Line Items
Risk/Return [Heading]		Fund Summary Fund /Class: Fidelity® Mega Cap Stock Fund /Fidelity Advisor® Mega Cap Stock Fund A, M, C, I, Z
Objective [Heading]		Investment Objective
Objective, Primary [Text Block]		Fidelity® Mega Cap Stock Fund seeks high total return through a combination of current income and capital appreciation.
Expense Heading [Optional Text]		Fee Table
Expense Narrative [Text Block]		The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 31 of the prospectus and in the sales charge waiver appendix to the prospectus.
Shareholder Fees Caption [Optional Text]		Shareholder fees
Operating Expenses Caption [Optional Text]		Annual Operating Expenses
Portfolio Turnover [Heading]		Portfolio Turnover
Portfolio Turnover [Text Block]		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 fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 15 % of the average value of its portfolio.
Portfolio Turnover, Rate		15.00%
Expenses Deferred Charges [Text Block]		Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
Expense Breakpoint Discounts [Text]		You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 31 of the prospectus
Expense Breakpoint, Minimum Investment Required [Amount]		$ 50,000
Expense Example Narrative [Text Block]		This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:
Strategy [Heading]		Principal Investment Strategies
Strategy Narrative [Text Block]		Normally investing at least 80% of assets in common stocks of companies with mega market capitalizations. The Adviser generally defines mega market capitalization companies as those whose market capitalization is similar to the market capitalization of companies in the Russell Top 200 ® Index or the S&P 100 ® Index. Common stocks (including depositary receipts evidencing ownership of common stock) are a type of equity security that represents an ownership interest in an issuer. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Investing in domestic and foreign issuers. Investing in either "growth" stocks or "value" stocks or both. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.
Bar Chart and Performance Table [Heading]		Performance
Performance Narrative [Text Block]		The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.
Performance Information Illustrates Variability of Returns [Text]		The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.
Performance Availability Website Address [Text]		institutional.fidelity.com
Performance Past Does Not Indicate Future [Text]		Past performance (before and after taxes) is not an indication of future performance.
Bar Chart [Heading]		Year-by-Year Returns
Bar Chart Narrative [Text Block]		The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.
Bar Chart Does Not Reflect Sales Loads [Text]		The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.
Year to Date Return, Label [Optional Text]		Year-to-Date Return
Bar Chart, Year to Date Return, Date		Jun. 30, 2025
Bar Chart, Year to Date Return		11.91%
Highest Quarterly Return, Label [Optional Text]		Highest Quarter Return
Highest Quarterly Return, Date		Dec. 31, 2020
Highest Quarterly Return		18.80%
Lowest Quarterly Return, Label [Optional Text]		Lowest Quarter Return
Lowest Quarterly Return, Date		Mar. 31, 2020
Lowest Quarterly Return		(22.99%)
Performance Table Heading		Average Annual Returns
Performance Table Does Reflect Sales Loads		Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.
Performance Table Uses Highest Federal Rate		After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.
Performance Table Not Relevant to Tax Deferred		The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).
Performance Table One Class of after Tax Shown [Text]		After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.
Performance Table Explanation after Tax Higher		Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.
Performance Table Narrative		Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.
FidelityMegaCapStockFund-AMCIZPRO | Fidelity Mega Cap Stock Fund | After Taxes on Distributions | Fidelity Advisor Mega Cap Stock Fund - Class A
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Return After Taxes on Distributions
Average Annual Return, Percent			17.65%											12.70%	9.81%
FidelityMegaCapStockFund-AMCIZPRO | Fidelity Mega Cap Stock Fund | After Taxes on Distributions and Sales | Fidelity Advisor Mega Cap Stock Fund - Class A
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Return After Taxes on Distributions and Sale of Fund Shares
Average Annual Return, Percent			11.34%											10.77%	8.92%
FidelityMegaCapStockFund-AMCIZPRO | Fidelity Mega Cap Stock Fund | SP001
Prospectus Line Items
Average Annual Return, Label [Optional Text]			S&P 500® Index
Average Annual Return, Percent			25.02%											14.53%	13.10%
FidelityMegaCapStockFund-AMCIZPRO | Fidelity Mega Cap Stock Fund | RS009
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Russell Top 200® Index
Average Annual Return, Percent			27.44%											15.75%	14.03%
FidelityGrowthDiscoveryFund-KPRO | Fidelity Growth Discovery Fund | Fidelity Growth Discovery Fund - Class K
Prospectus Line Items
Management Fees (as a percentage of Assets)	[4]	0.54%
Distribution and Service (12b-1) Fees		0.00%
Other Expenses (as a percentage of Assets):		0.00%
Expenses (as a percentage of Assets)		0.54%
Expense Example, with Redemption, 1 Year		$ 55
Expense Example, with Redemption, 3 Years		173
Expense Example, with Redemption, 5 Years		302
Expense Example, with Redemption, 10 Years		$ 677
Average Annual Return, Label [Optional Text]			Class K
Average Annual Return, Percent			30.23%											18.78%	16.52%
Annual Return [Percent]				30.23%	35.76%	(24.35%)	23.10%	43.61%	33.93%	(0.14%)	34.83%	0.83%	7.29%
FidelityGrowthDiscoveryFund-KPRO | Fidelity Growth Discovery Fund
Prospectus Line Items
Risk/Return [Heading]		Fund Summary Fund /Class: Fidelity® Growth Discovery Fund /K
Objective [Heading]		Investment Objective
Objective, Primary [Text Block]		Fidelity® Growth Discovery Fund seeks capital appreciation.
Expense Heading [Optional Text]		Fee Table
Expense Narrative [Text Block]		The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text]		Shareholder fees
Shareholder Fee, Other		$ 0
Operating Expenses Caption [Optional Text]		Annual Operating Expenses
Portfolio Turnover [Heading]		Portfolio Turnover
Portfolio Turnover [Text Block]		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 fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 60 % of the average value of its portfolio.
Portfolio Turnover, Rate		60.00%
Expense Example Narrative [Text Block]		This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:
Strategy [Heading]		Principal Investment Strategies
Strategy Narrative [Text Block]		Normally investing primarily in common stocks. Investing in companies that Fidelity Management & Research Company LLC (FMR) believes have above-average growth potential (stocks of these companies are often called "growth" stocks). Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments. Effective December 11, 2025, normally investing at least 80% of assets in securities of growth companies. Growth companies are companies the Adviser believes have above average growth potential. The Adviser considers a number of factors in determining a company's growth potential, such as whether the company is included in a third-party growth benchmark or classified as a growth company by a third-party vendor, if the company's projected earnings per share growth, sales growth per share or free cash flow growth or its trailing earnings per share growth is above the equity market median, if the company's research and development expenses exceed sales, general and administrative expenses, or if the company is raising capital to grow, fund or expand its business. A company's growth potential can be determined under any of these factors. Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.
Bar Chart and Performance Table [Heading]		Performance
Performance Narrative [Text Block]		The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.
Performance Information Illustrates Variability of Returns [Text]		The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.
Performance Availability Website Address [Text]		www.401k.com
Performance Past Does Not Indicate Future [Text]		Past performance is not an indication of future performance.
Bar Chart [Heading]		Year-by-Year Returns
Year to Date Return, Label [Optional Text]		Year-to-Date Return
Bar Chart, Year to Date Return, Date		Jun. 30, 2025
Bar Chart, Year to Date Return		6.26%
Highest Quarterly Return, Label [Optional Text]		Highest Quarter Return
Highest Quarterly Return, Date		Jun. 30, 2020
Highest Quarterly Return		31.45%
Lowest Quarterly Return, Label [Optional Text]		Lowest Quarter Return
Lowest Quarterly Return, Date		Jun. 30, 2022
Lowest Quarterly Return		(17.99%)
Performance Table Heading		Average Annual Returns
FidelityGrowthDiscoveryFund-KPRO | Fidelity Growth Discovery Fund | RS007
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Russell 3000® Growth Index
Average Annual Return, Percent			32.46%											18.25%	16.22%
FidelityGrowthDiscoveryFund-KPRO | Fidelity Growth Discovery Fund | RS003
Prospectus Line Items
Average Annual Return, Label [Optional Text]			Russell 3000® Index
Average Annual Return, Percent			23.81%											13.86%	12.55%
FidelityFund-KPRO | Fidelity Fund | Fidelity Fund - Class K
Prospectus Line Items
Management Fees (as a percentage of Assets)		0.34%
Distribution and Service (12b-1) Fees		0.00%
Other Expenses (as a percentage of Assets):		0.00%
Expenses (as a percentage of Assets)		0.34%
Expense Example, with Redemption, 1 Year		$ 35
Expense Example, with Redemption, 3 Years		109
Expense Example, with Redemption, 5 Years		191
Expense Example, with Redemption, 10 Years		$ 431
Average Annual Return, Label [Optional Text]			Class K
Average Annual Return, Percent			27.24%											15.85%	13.53%
Annual Return [Percent]				27.24%	31.03%	(25.81%)	33.31%	26.55%	33.58%	(5.16%)	23.95%	4.93%	3.47%
FidelityFund-KPRO | Fidelity Fund
Prospectus Line Items
Risk/Return [Heading]		Fund Summary Fund /Class: Fidelity® Fund /K
Objective [Heading]		Investment Objective
Objective, Primary [Text Block]		Fidelity® Fund seeks long-term capital growth.
Expense Heading [Optional Text]		Fee Table
Expense Narrative [Text Block]		The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Optional Text]		Shareholder fees
Shareholder Fee, Other		$ 0
Operating Expenses Caption [Optional Text]		Annual Operating Expenses
Portfolio Turnover [Heading]		Portfolio Turnover
Portfolio Turnover [Text Block]		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 fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 31 % of the average value of its portfolio.
Portfolio Turnover, Rate		31.00%
Expense Example Narrative [Text Block]		This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:
Strategy [Heading]		Principal Investment Strategies
Strategy Narrative [Text Block]		Normally investing primarily in common stocks. Potentially investing a portion of assets in bonds, including lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). Investing in domestic and foreign issuers. Investing in either "growth" stocks or "value" stocks or both. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.
Bar Chart and Performance Table [Heading]		Performance
Performance Narrative [Text Block]		The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index over various periods of time. The index description appears in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.
Performance Information Illustrates Variability of Returns [Text]		The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index over various periods of time.
Performance Availability Website Address [Text]		www.401k.com
Performance Past Does Not Indicate Future [Text]		Past performance is not an indication of future performance.
Bar Chart [Heading]		Year-by-Year Returns
Year to Date Return, Label [Optional Text]		Year-to-Date Return
Bar Chart, Year to Date Return, Date		Jun. 30, 2025
Bar Chart, Year to Date Return		6.93%
Highest Quarterly Return, Label [Optional Text]		Highest Quarter Return
Highest Quarterly Return, Date		Jun. 30, 2020
Highest Quarterly Return		23.43%
Lowest Quarterly Return, Label [Optional Text]		Lowest Quarter Return
Lowest Quarterly Return, Date		Jun. 30, 2022
Lowest Quarterly Return		(18.59%)
Performance Table Heading		Average Annual Returns
FidelityFund-KPRO | Fidelity Fund | SP001
Prospectus Line Items
Average Annual Return, Label [Optional Text]			S&P 500® Index
Average Annual Return, Percent			25.02%											14.53%	13.10%
Document Type		485BPOS
Registrant Name		Fidelity Hastings Street Trust

[1] A The management fee comprises a basic fee, which may vary by class, that is adjusted up or down by a maximum of 0.20% based on the performance of the fund or a designated class of the fund relative to that of the Russell 3000® Growth Index. Please see "Fund Services - Fund Management - Advisory Fee(s)" for additional information.

[2] A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.

[3] B On Class C shares redeemed less than one year after purchase.

[4] A The management fee comprises a basic fee, which may vary by class, that is adjusted up or down by a maximum of 0.20% based on the performance of the fund or a designated class of the fund relative to that of the Russell 3000® Growth Index. Please see "Fund Services - Fund Management - Advisory Fee(s)" for additional information.