Note 16 - Commitments and Contingencies	9 Months Ended
Sep. 30, 2025
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	Note 16 — Commitments and Contingencies Commitments and contingencies may arise in the normal course of business. *Investment Commitments* As of September 30, 2025, the Company had capital commitments totaling $15.0 million to fund our seeded investment product in a private market strategy. These commitments are callable on demand at any time prior to their respective expiration date, and the timing of the funding is uncertain. The unfunded capital commitments are not recorded on the Company's Condensed Consolidated Balance Sheets. The Company intends to make additional capital commitments periodically to support the launch and growth of new investment products. *Litigation and Other Regulatory Matters* We are periodically involved in various legal proceedings and other regulatory matters. Sandra Schissler v. Janus Henderson US (Holdings) Inc., Janus Henderson Advisory Committee, and John and Jane Does 1-30 On September 9, 2022, a class action complaint, captioned Schissler v. Janus Henderson US (Holdings) Inc., et al., was filed in the United States District Court for the District of Colorado. Named as defendants are Janus Henderson US (Holdings) Inc. (“Janus US Holdings”) and the Advisory Committee to the Janus 401(k) and Employee Stock Ownership Plan (the “Plan”). The complaint purports to be brought on behalf of a class consisting of participants and beneficiaries of the Plan that invested in Janus Henderson funds on or after September 9, 2016. On January 10, 2023, an amended complaint was filed against the same defendants, naming two additional plaintiffs, Karly Sissel and Derrick Hittson. As amended, the complaint alleges that for the period since September 9, 2016, among other things, the defendants breached fiduciary duties of loyalty and prudence by (i) selecting higher-cost Janus Henderson funds over less expensive investment options, (ii) retaining Janus Henderson funds despite their alleged underperformance and (iii) failing to consider actively managed funds outside of Janus Henderson to add as investment options. The amended complaint also alleges that Janus US Holdings failed to monitor the Advisory Committee with respect to the foregoing. The amended complaint seeks various declaratory, equitable and monetary relief in unspecified amounts. On January 22, 2024, the district court entered an order granting in part and denying in part Janus US Holdings' motion to dismiss. The parties thereafter conducted fact and expert discovery, which was completed on May 27, 2025. On July 11, 2025, the defendants filed a motion for summary judgment with respect to all of the claims asserted in the complaint, as well as a motion to exclude certain opinions offered by the plaintiffs’ experts. Also on July 11, 2025, the plaintiffs filed a motion for partial summary judgment with respect to one element of their fiduciary duty claim, and a motion to exclude certain opinions offered by the defendants’ damages expert. Those motions have been fully briefed but no decision has been issued. On September 29, 2025, the district court entered an order scheduling an eight-day trial starting on July 20, 2026. Janus US Holdings believes that it has substantial defenses and intends to vigorously defend against these claims.

Note 16 - Commitments and Contingencies

9 Months Ended

Sep. 30, 2025

Commitments and Contingencies Disclosure [Text Block]

Note 16 — Commitments and Contingencies

Commitments and contingencies may arise in the normal course of business.

Investment Commitments

As of September 30, 2025, the Company had capital commitments totaling $15.0 million to fund our seeded investment product in a private market strategy. These commitments are callable on demand at any time prior to their respective expiration date, and the timing of the funding is uncertain. The unfunded capital commitments are not recorded on the Company's Condensed Consolidated Balance Sheets. The Company intends to make additional capital commitments periodically to support the launch and growth of new investment products.

Litigation and Other Regulatory Matters

We are periodically involved in various legal proceedings and other regulatory matters.

Sandra Schissler v. Janus Henderson US (Holdings) Inc., Janus Henderson Advisory Committee, and John and Jane Does 1-30

On September 9, 2022, a class action complaint, captioned Schissler v. Janus Henderson US (Holdings) Inc., et al., was filed in the United States District Court for the District of Colorado. Named as defendants are Janus Henderson US (Holdings) Inc. (“Janus US Holdings”) and the Advisory Committee to the Janus 401(k) and Employee Stock Ownership Plan (the “Plan”). The complaint purports to be brought on behalf of a class consisting of participants and beneficiaries of the Plan that invested in Janus Henderson funds on or after September 9, 2016. On January 10, 2023, an amended complaint was filed against the same defendants, naming two additional plaintiffs, Karly Sissel and Derrick Hittson. As amended, the complaint alleges that for the period since September 9, 2016, among other things, the defendants breached fiduciary duties of loyalty and prudence by (i) selecting higher-cost Janus Henderson funds over less expensive investment options, (ii) retaining Janus Henderson funds despite their alleged underperformance and (iii) failing to consider actively managed funds outside of Janus Henderson to add as investment options. The amended complaint also alleges that Janus US Holdings failed to monitor the Advisory Committee with respect to the foregoing. The amended complaint seeks various declaratory, equitable and monetary relief in unspecified amounts. On January 22, 2024, the district court entered an order granting in part and denying in part Janus US Holdings' motion to dismiss. The parties thereafter conducted fact and expert discovery, which was completed on May 27, 2025.

On July 11, 2025, the defendants filed a motion for summary judgment with respect to all of the claims asserted in the complaint, as well as a motion to exclude certain opinions offered by the plaintiffs’ experts. Also on July 11, 2025, the plaintiffs filed a motion for partial summary judgment with respect to one element of their fiduciary duty claim, and a motion to exclude certain opinions offered by the defendants’ damages expert. Those motions have been fully briefed but no decision has been issued. On September 29, 2025, the district court entered an order scheduling an eight-day trial starting on July 20, 2026. Janus US Holdings believes that it has substantial defenses and intends to vigorously defend against these claims.