Risk/Return Detail Data - VIPSectorFunds-InvestorComboPRO	Apr. 30, 2025 USD ($)
Risk/Return:
Registrant Name	Variable Insurance Products Fund IV
VIPSectorFunds-InvestorComboPRO | VIP Energy Portfolio
Risk/Return:
Risk/Return [Heading]	Fund Summary Fund /Class: VIP Energy Portfolio /Investor Class
Objective [Heading]	Investment Objective
Objective, Primary [Text Block]	VIP Energy Portfolio seeks capital appreciation.
Expense [Heading]	Fee Table
Expense Narrative [Text Block]	The following table describes the fees and expenses that may be incurred, directly or indirectly, when you, as a variable product owner, buy, hold, and sell interests in a separate account that invests in shares of the fund. The table does not include any fees or other expenses of any variable annuity or variable life insurance product; if it did, overall fees and expenses would be higher.
Shareholder Fees Caption [Text]	Fees
(fees paid directly from your investment)
Operating Expenses Caption [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. 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%
Expenses Restated to Reflect Current [Text]	Adjusted to reflect current fees.
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. This example does not include any fees or other expenses of any variable annuity or variable life insurance product; if it did, overall expenses would be higher. For every $10,000 invested, here's how much you, as a variable product owner, would pay in total expenses if all interests in a separate account that invests in shares of the fund were redeemed at the end of each time period indicated:
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the energy field including the conventional areas of oil, gas, electricity and coal, and newer sources of energy such as nuclear, geothermal, oil shale, and solar power. These companies may include, for example, integrated oil companies; drilling contractors and rig owners; drilling rig and equipment manufacturers and providers of supplies and services to companies engaged in oil and gas drilling; companies engaged in the exploration, production, refining, marketing, storage, or transportation of oil, gas, and/or refined products; and companies involved in the production and mining of coal, related products, and other consumable fuels. For purposes of the fund's policy to normally invest at least 80% of its assets in securities of companies principally engaged in the business activity or activities identified for the fund, Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. 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. 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.
Strategy Portfolio Concentration [Text]	Normally investing at least 80% of assets in securities of companies principally engaged in the energy field including the conventional areas of oil, gas, electricity and coal, and newer sources of energy such as nuclear, geothermal, oil shale, and solar power.
Risk [Heading]	Principal Investment Risks
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. Returns for shares of the fund do not include the effect of any sales charges or other expenses of any variable annuity or variable life insurance product; if they did, returns for shares of the fund would be lower.
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 Past Does Not Indicate Future [Text]	Past performance is not an indication of future performance.
Bar Chart [Heading]	Year-by-Year Returns
Bar Chart Does Not Reflect Sales Loads [Text]	Returns for shares of the fund do not include the effect of any sales charges or other expenses of any variable annuity or variable life insurance product; if they did, returns for shares of the fund would be lower.
Highest Quarterly Return, Label	Highest Quarter Return
Highest Quarterly Return, Date	Mar. 31, 2022
Highest Quarterly Return	39.88%
Lowest Quarterly Return, Label	Lowest Quarter Return
Lowest Quarterly Return, Date	Mar. 31, 2020
Lowest Quarterly Return	(52.46%)
Performance Table Heading	Average Annual Returns
VIPSectorFunds-InvestorComboPRO | VIP Energy Portfolio | VIP Energy Portfolio - Investor Class
Risk/Return:
Management fee	0.66%	[1]
Distribution and/or Service (12b-1) fees	none
Other expenses	0.02%	[1]
Total annual operating expenses	0.68%
1 year	$ 69
3 years	218
5 years	379
10 years	$ 847
2015	(20.58%)
2016	33.70%
2017	(2.57%)
2018	(24.65%)
2019	9.98%
2020	(32.80%)
2021	55.16%
2022	63.13%
2023	0.91%
2024	4.20%
VIPSectorFunds-InvestorComboPRO | VIP Energy Portfolio | Return Before Taxes | VIP Energy Portfolio - Investor Class
Risk/Return:
Label	Investor Class
Past 1 year	4.20%
Past 5 years	12.33%
Past 10 years	4.37%
VIPSectorFunds-InvestorComboPRO | VIP Energy Portfolio | SP001
Risk/Return:
Label	S&P 500® Index
Past 1 year	25.02%
Past 5 years	14.53%
Past 10 years	13.10%
VIPSectorFunds-InvestorComboPRO | VIP Energy Portfolio | F1509
Risk/Return:
Label	MSCI U.S. IMI Energy 25-50 Index
Past 1 year	6.67%
Past 5 years	12.76%
Past 10 years	4.51%

[1] A Adjusted to reflect current fees.