Janus Henderson High-Yield Fund Investment Strategy - Class A C S I N R T Shares [Member] - Janus Henderson High-Yield Fund	Jun. 30, 2025
Prospectus [Line Items]
Strategy [Heading]	<span style="color:#FFFFFF;font-family:Times New Roman;font-size:10.45pt;font-weight:bold;margin-left:0.0pt;text-transform:uppercase;">Principal investment strategies</span>
Strategy Narrative [Text Block]	The Fund pursues its investment objectives by investing, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in high-yield securities rated below investment grade (also known as “junk” bonds). Securities rated below investment grade may include their unrated equivalents or other high-yielding securities portfolio management believes offer attractive risk/return characteristics. The Fund may at times invest all of its assets in such securities. The Fund may also invest in money market instruments and foreign debt securities. The Fund may also invest in floating rate obligations, such as collateralized loan obligations, floating rate senior secured syndicated bank loans, floating rate unsecured loans, and other floating rate bonds, loans and notes. The Fund may also invest in securities that have contractual restrictions that prohibit or limit their public resale, which may include Rule 144A securities. Due to the nature of the securities in which the Fund invests, it may have relatively high portfolio turnover compared to other funds. Additionally, the Fund may invest its assets in derivatives. Derivative instruments have a value derived from, or directly linked to, an underlying asset, such as fixed-income securities, commodities, currencies, interest rates, or market indices. The Fund’s exposure to derivatives will vary. For purposes of meeting its 80% investment policy, the Fund may include derivatives that have characteristics similar to the securities in which the Fund may directly invest. In particular, the Fund may invest in swaps, including index credit default swaps, to increase or decrease the Fund’s exposure to a particular market. Portfolio management’s investment process is research-driven, incorporating “top-down” and “bottom-up” factors to identify and manage exposure to risks across sectors, industries, and individual investments. Portfolio management evaluates expected risk-adjusted returns on a portfolio and position level by analyzing fundamentals, valuations, and market technical indicators. This research encompasses both traditional fundamental analysis and data driven quantitative models and signals from such models.As part of its investment process, portfolio management considers environmental, social, and governance (“ESG”) risks and opportunities (“ESG Factors”) that it believes are financially material, alongside other fundamental investment factors. Examples of potential financially material ESG Factors include: corporate governance, company culture, exposure to climate change, and human capital management. To assess ESG Factors, portfolio management uses issuer reports, third-party data, and internally-generated analyses and may engage directly with issuers. ESG Factors are one of many considerations in the investment decision-making process, may not be determinative in deciding to include or exclude an investment from the portfolio, and may not be considered for every investment decision.The Fund may seek to earn additional income through lending its securities to certain qualified broker-dealers and institutions, in an amount equal to up to one-third of its total assets as determined at the time of the loan origination.

Janus Henderson High-Yield Fund Investment Strategy - Class A C S I N R T Shares [Member] - Janus Henderson High-Yield Fund

Jun. 30, 2025

<span style="color:#FFFFFF;font-family:Times New Roman;font-size:10.45pt;font-weight:bold;margin-left:0.0pt;text-transform:uppercase;">Principal investment strategies</span>

Strategy Narrative [Text Block]

The Fund pursues its investment objectives by investing, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in high-yield securities rated below investment grade (also known as “junk” bonds). Securities rated below investment grade may include their unrated equivalents or other high-yielding securities portfolio management believes offer attractive risk/return characteristics. The Fund may at times invest all of its assets in such securities. The Fund may also invest in money market instruments and foreign debt securities. The Fund may also invest in floating rate obligations, such as collateralized loan obligations, floating rate senior secured syndicated bank loans, floating rate unsecured loans, and other floating rate bonds, loans and notes. The Fund may also invest in securities that have contractual restrictions that prohibit or limit their public resale, which may include Rule 144A securities. Due to the nature of the securities in which the Fund invests, it may have relatively high portfolio turnover compared to other funds. Additionally, the Fund may invest its assets in derivatives. Derivative instruments have a value derived from, or directly linked to, an underlying asset, such as fixed-income securities, commodities, currencies, interest rates, or market indices. The Fund’s exposure to derivatives will vary. For purposes of meeting its 80% investment policy, the Fund may include derivatives that have characteristics similar to the securities in which the Fund may directly invest. In particular, the Fund may invest in swaps, including index credit default swaps, to increase or decrease the Fund’s exposure to a particular market. Portfolio management’s investment process is research-driven, incorporating “top-down” and “bottom-up” factors to identify and manage exposure to risks across sectors, industries, and individual investments. Portfolio management evaluates expected risk-adjusted returns on a portfolio and position level by analyzing fundamentals, valuations, and market technical indicators. This research encompasses both traditional fundamental analysis and data driven quantitative models and signals from such models.As part of its investment process, portfolio management considers environmental, social, and governance (“ESG”) risks and opportunities (“ESG Factors”) that it believes are financially material, alongside other fundamental investment factors. Examples of potential financially material ESG Factors include: corporate governance, company culture, exposure to climate change, and human capital management. To assess ESG Factors, portfolio management uses issuer reports, third-party data, and internally-generated analyses and may engage directly with issuers. ESG Factors are one of many considerations in the investment decision-making process, may not be determinative in deciding to include or exclude an investment from the portfolio, and may not be considered for every investment decision.The Fund may seek to earn additional income through lending its securities to certain qualified broker-dealers and institutions, in an amount equal to up to one-third of its total assets as determined at the time of the loan origination.