| Cover | 12 Months Ended |
| Dec. 31, 2022 | |
| Document Information [Line Items] | |
| Document Type | DEF 14A |
| Amendment Flag | false |
| Entity Information [Line Items] | |
| Entity Registrant Name | JANUS HENDERSON GROUP PLC |
| Entity Central Index Key | 0001274173 |
| Pay vs Performance Disclosure | 12 Months Ended | 36 Months Ended | ||||||
| Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2022 | |||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Pay vs Performance [Table Text Block] | Pay Versus Performance Table for Fiscal Year 2022 The Pay Versus Performance Table below discloses the relationship between the compensation actually paid to the executive officers and the Company’s financial performance during the years ended December 31, 2020, 2021, and 2022. The compensation information presented in this table is different from compensation information presented in the Summary Compensation Table above. The differences can largely be attributed to variation in the treatment of stock awards in each of these tables. ■ The compensation presented in the “ 2022 Compensation for the CEO and Other NEOs ■ In accordance with SEC rules, the Stock Awards column in the Summary Compensation Table includes the aggregate grant date fair values of the RSUs granted during 2022, even though the number of RSUs granted was determined based on the 2021 performance of the executive officers. ■ The Pay Versus Performance Table below differs from both the information presented in the CD&A and in the Summary Compensation Table, because it calculates actual compensation based on different methodologies, including the value of outstanding unvested stock awards as of December 31, 2022. Average Average Value of Initial Fixed $100 Year Summary Summary Compensation (1) Compensation (1) Total for (2) Actually Paid Total Peer Group (3) Net Adjusted (4)(5) 2022 7,947,815 4,515,893 8,027,246 (2,057,211 ) 3,259,428 2,559,255 113.22 128.15 372.4 33.8 2021 — 9,317,046 — 15,802,892 2,613,369 3,185,241 190.36 171.06 620.0 43.4 2020 — 8,388,794 — 12,221,851 2,046,390 2,565,353 141.94 115.88 130.3 38.1 (1) The amounts in the following table represent each of the amounts deducted and added to the equity award values for our Principal Executive Officer (“ PEO ” CAP ” Year PEO Name Grant Date (i) Year-End Fair Change in Fair Value Change in Dollar Value of (ii) Total Equity (iii) 2022 Ali Dibadj (5,000,022 ) 4,916,409 — — — 163,044 79,431 2022 Richard Weil (1,000,027 ) 697,321 (2,409,840 ) — (3,895,246 ) 34,688 (6,573,104 ) 2021 Richard Weil (1,950,007 ) 3,607,008 4,928,291 — (101,092 ) 1,646 6,485,846 2020 Richard Weil (1,856,267 ) 3,151,292 2,504,043 — 3,233 30,756 3,833,057 (i) Represents the deduction of amounts reported in the Stock Awards column of the Summary Compensation Table. (ii) Represents dividends paid or accrued on stock awards in 2022 prior to the vesting date(s) that are not otherwise reflected in the Compensation Actually Paid to the applicable PEO. (iii) Represents the total adjustments to the Summary Compensation Table in respect of equity awards for the applicable year, as reflected in Compensation Actually Paid. (2) The amounts in the following table represent each of the amounts deducted and added to the equity award values for the non-PEO NEOs for the applicable year for purposes of computing the “compensation actually paid” amounts appearing in the Pay Versus Performance Table: Year NEO Names Grant Date Year-End Change in Fair Fair Value Change in Dollar Value of (i) Total Equity (ii) 2022 (iii) 2022 AVERAGE (1,875,254 ) 1,320,305 (377,728 ) 474,002 (340,406 ) 98,908 (700,173 ) 2021 (iv) 2021 AVERAGE (547,511 ) 781,573 284,199 — (11,677 ) 65,288 571,872 2020 (v) 2020 AVERAGE (444,495 ) 692,739 249,241 — (32,744 ) 54,222 518,963 (i) Represents dividends paid or accrued on stock awards in 2022 prior to the vesting date(s) that are not otherwise reflected in the Compensation Actually Paid to the non-PEO NEOs. (ii) Represents the total adjustments to the Average Summary Compensation Table Total in respect of equity awards for the applicable year, as reflected in Compensation Actually Paid. (iii) 2022 NEOs include: Mr. Thompson, Mses. Cain, Fogo, Rosenberg, and Krueger. Mr. Thompson served as our Interim Chief Executive Officer from April 1, 2022, until Mr. Dibadj’s appointment on June 21, 2022. In connection with Mr. Thompson’s interim role, he continued to receive the same salary he received in 2022 for his role as Chief Financial Officer. Accordingly, Mr. Thompson’s 2022 compensation has been included in the average compensation column for our non-PEO NEOs. (iv) 2021 NEOs include: Mr. Thompson, Mses. Cain, Fogo, and Rosenberg. (v) 2020 NEOs include: Mr. Thompson, Mses. Cain, Fogo, and Rosenberg. (3) The companies included in the peer group total shareholder return calculations are the publicly traded companies included in the S&P U.S. BMI Asset Management & Custody Banks Index used by the Company for purposes of disclosing our cumulative total shareholder return in our Annual Report on Form 10-K for the fiscal year ended December 31, 2022. The S&P US BMI Asset Management & Custody Banks Index is a market-value weighted index of 40 asset management companies. (4) In addition to financial results reported in accordance with GAAP, we report certain financial measures on a non-GAAP basis. These measures are not in accordance with, or a substitute for, GAAP, and our financial measures may differ from the non-GAAP financial measures used by other companies. For additional information, see Annex A Reconciliation of Non-GAAP Financial Measures (5) Adjusted operating margin is adjusted operating income divided by adjusted revenue for 2022. This measure has been designated as the “Company-Selected Measure” for 2022, in accordance with SEC rules, and represents the most important financial performance measure (that is not otherwise required to be disclosed in the table) used by the Company to link compensation actually paid to our NEOs in 2022. | |||||||
| Company Selected Measure Name | Adjusted Operating Margin | |||||||
| Peer Group Issuers, Footnote [Text Block] | (3)The companies included in the peer group total shareholder return calculations are the publicly traded companies included in the S&P U.S. BMI Asset Management & Custody Banks Index used by the Company for purposes of disclosing our cumulative total shareholder return in our Annual Report on Form 10-K for the fiscal year ended December 31, 2022. The S&P US BMI Asset Management & Custody Banks Index is a market-value weighted index of 40 asset management companies. | |||||||
| PEO Total Compensation Amount | $ 9,317,046 | $ 8,388,794 | ||||||
| PEO Actually Paid Compensation Amount | [1] | 15,802,892 | 12,221,851 | |||||
| Adjustment To PEO Compensation, Footnote [Text Block] | (1) The amounts in the following table represent each of the amounts deducted and added to the equity award values for our Principal Executive Officer (“ PEO ” CAP ” Year PEO Name Grant Date (i) Year-End Fair Change in Fair Value Change in Dollar Value of (ii) Total Equity (iii) 2022 Ali Dibadj (5,000,022 ) 4,916,409 — — — 163,044 79,431 2022 Richard Weil (1,000,027 ) 697,321 (2,409,840 ) — (3,895,246 ) 34,688 (6,573,104 ) 2021 Richard Weil (1,950,007 ) 3,607,008 4,928,291 — (101,092 ) 1,646 6,485,846 2020 Richard Weil (1,856,267 ) 3,151,292 2,504,043 — 3,233 30,756 3,833,057 | |||||||
| Non-PEO NEO Average Total Compensation Amount | [2] | $ 3,259,428 | 2,613,369 | 2,046,390 | ||||
| Non-PEO NEO Average Compensation Actually Paid Amount | 2,559,255 | 3,185,241 | 2,565,353 | |||||
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | (2) The amounts in the following table represent each of the amounts deducted and added to the equity award values for the non-PEO NEOs for the applicable year for purposes of computing the “compensation actually paid” amounts appearing in the Pay Versus Performance Table: Year NEO Names Grant Date Year-End Change in Fair Fair Value Change in Dollar Value of (i) Total Equity (ii) 2022 (iii) 2022 AVERAGE (1,875,254 ) 1,320,305 (377,728 ) 474,002 (340,406 ) 98,908 (700,173 ) 2021 (iv) 2021 AVERAGE (547,511 ) 781,573 284,199 — (11,677 ) 65,288 571,872 2020 (v) 2020 AVERAGE (444,495 ) 692,739 249,241 — (32,744 ) 54,222 518,963 (i) Represents dividends paid or accrued on stock awards in 2022 prior to the vesting date(s) that are not otherwise reflected in the Compensation Actually Paid to the non-PEO NEOs. (ii) Represents the total adjustments to the Average Summary Compensation Table Total in respect of equity awards for the applicable year, as reflected in Compensation Actually Paid. (iii) 2022 NEOs include: Mr. Thompson, Mses. Cain, Fogo, Rosenberg, and Krueger. Mr. Thompson served as our Interim Chief Executive Officer from April 1, 2022, until Mr. Dibadj’s appointment on June 21, 2022. In connection with Mr. Thompson’s interim role, he continued to receive the same salary he received in 2022 for his role as Chief Financial Officer. Accordingly, Mr. Thompson’s 2022 compensation has been included in the average compensation column for our non-PEO NEOs. (iv) 2021 NEOs include: Mr. Thompson, Mses. Cain, Fogo, and Rosenberg. (v) 2020 NEOs include: Mr. Thompson, Mses. Cain, Fogo, and Rosenberg. | |||||||
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | ||||||||
| Compensation Actually Paid vs. Net Income [Text Block] | Note: The SEC requires companies to compare compensation actually paid to our NEOs (including the PEO) and net income, however, we do not rely on net income in the determination of NEO compensation. (1) The “CAP to PEO” amount for 2022 represents compensation paid to Ali Dibadj. “CAP to PEO” amounts for 2021 and 2020 represents compensation paid to Richard Weil. | |||||||
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | ||||||||
| Total Shareholder Return Vs Peer Group [Text Block] | ||||||||
| Total Shareholder Return Amount | 113.22 | 190.36 | 141.94 | |||||
| Peer Group Total Shareholder Return Amount | [3] | 128.15 | 171.06 | 115.88 | ||||
| Net Income (Loss) | $ 372.4 | $ 620 | $ 130.3 | |||||
| Company Selected Measure Amount | [4],[5] | 33.8 | 43.4 | 38.1 | ||||
| Additional 402(v) Disclosure [Text Block] | Most Important Performance Measures Adjusted Operating Margin Annual Net New Revenue Total Shareholder Return % Assets Outperforming Benchmarks | |||||||
| Measure [Axis]: 1 | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Measure Name | Adjusted Operating Margin | |||||||
| Measure [Axis]: 2 | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Measure Name | Annual Net New Revenue | |||||||
| Measure [Axis]: 3 | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Measure Name | Total Shareholder Return | |||||||
| Measure [Axis]: 4 | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Measure Name | % Assets Outperforming Benchmarks | |||||||
| Dibadj [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| PEO Total Compensation Amount | $ 7,947,815 | |||||||
| PEO Actually Paid Compensation Amount | [1] | $ 8,027,246 | ||||||
| PEO Name | Ali Dibadj | |||||||
| Dibadj [Member] | Adjustment Type 1 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | [6] | $ (5,000,022) | ||||||
| Dibadj [Member] | Adjustment Type 2 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | 4,916,409 | |||||||
| Dibadj [Member] | Adjustment Type 6 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | [7] | 163,044 | ||||||
| Dibadj [Member] | Adjustment Type 7 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | [8] | 79,431 | ||||||
| Weil [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| PEO Total Compensation Amount | 4,515,893 | |||||||
| PEO Actually Paid Compensation Amount | [1] | (2,057,211) | ||||||
| PEO Name | Richard Weil | |||||||
| Weil [Member] | Adjustment Type 1 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | [6] | (1,000,027) | $ (1,950,007) | $ (1,856,267) | ||||
| Weil [Member] | Adjustment Type 2 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | 697,321 | 3,607,008 | 3,151,292 | |||||
| Weil [Member] | Adjustment Type 6 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | [7] | 34,688 | 1,646 | 30,756 | ||||
| Weil [Member] | Adjustment Type 7 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | (6,573,104) | 6,485,846 | 3,833,057 | |||||
| Weil [Member] | Adjustment Type 3 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | (2,409,840) | 4,928,291 | 2,504,043 | |||||
| Weil [Member] | Adjustment Type 5 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | (3,895,246) | (101,092) | 3,233 | |||||
| Non-PEO NEO [Member] | Adjustment Type 1 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | (1,875,254) | [9] | (547,511) | [10] | (444,495) | [11] | ||
| Non-PEO NEO [Member] | Adjustment Type 2 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | 1,320,305 | [9] | 781,573 | [10] | 692,739 | [11] | ||
| Non-PEO NEO [Member] | Adjustment Type 6 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | [12] | 98,908 | [9] | 65,288 | [10] | 54,222 | [11] | |
| Non-PEO NEO [Member] | Adjustment Type 7 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | (700,173) | 571,872 | [10] | 518,963 | [11] | |||
| Non-PEO NEO [Member] | Adjustment Type 3 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | (377,728) | [9] | 284,199 | [10] | 249,241 | [11] | ||
| Non-PEO NEO [Member] | Adjustment Type 5 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | (340,406) | [9] | $ (11,677) | [10] | $ (32,744) | [11] | ||
| Non-PEO NEO [Member] | Adjustment Type 4 [Member] | ||||||||
| Pay vs Performance Disclosure [Table] | ||||||||
| Adjustment to Compensation Amount | [9] | $ 474,002 | ||||||
| [1] (1) The amounts in the following table represent each of the amounts deducted and added to the equity award values for our Principal Executive Officer (“ PEO ” CAP ” Year PEO Name Grant Date (i) Year-End Fair Change in Fair Value Change in Dollar Value of (ii) Total Equity (iii) 2022 Ali Dibadj (5,000,022 ) 4,916,409 — — — 163,044 79,431 2022 Richard Weil (1,000,027 ) 697,321 (2,409,840 ) — (3,895,246 ) 34,688 (6,573,104 ) 2021 Richard Weil (1,950,007 ) 3,607,008 4,928,291 — (101,092 ) 1,646 6,485,846 2020 Richard Weil (1,856,267 ) 3,151,292 2,504,043 — 3,233 30,756 3,833,057 (2) The amounts in the following table represent each of the amounts deducted and added to the equity award values for the non-PEO NEOs for the applicable year for purposes of computing the “compensation actually paid” amounts appearing in the Pay Versus Performance Table: Year NEO Names Grant Date Year-End Change in Fair Fair Value Change in Dollar Value of (i) Total Equity (ii) 2022 (iii) 2022 AVERAGE (1,875,254 ) 1,320,305 (377,728 ) 474,002 (340,406 ) 98,908 (700,173 ) 2021 (iv) 2021 AVERAGE (547,511 ) 781,573 284,199 — (11,677 ) 65,288 571,872 2020 (v) 2020 AVERAGE (444,495 ) 692,739 249,241 — (32,744 ) 54,222 518,963 (i) Represents dividends paid or accrued on stock awards in 2022 prior to the vesting date(s) that are not otherwise reflected in the Compensation Actually Paid to the non-PEO NEOs. (ii) Represents the total adjustments to the Average Summary Compensation Table Total in respect of equity awards for the applicable year, as reflected in Compensation Actually Paid. (iii) 2022 NEOs include: Mr. Thompson, Mses. Cain, Fogo, Rosenberg, and Krueger. Mr. Thompson served as our Interim Chief Executive Officer from April 1, 2022, until Mr. Dibadj’s appointment on June 21, 2022. In connection with Mr. Thompson’s interim role, he continued to receive the same salary he received in 2022 for his role as Chief Financial Officer. Accordingly, Mr. Thompson’s 2022 compensation has been included in the average compensation column for our non-PEO NEOs. (iv) 2021 NEOs include: Mr. Thompson, Mses. Cain, Fogo, and Rosenberg. (v) 2020 NEOs include: Mr. Thompson, Mses. Cain, Fogo, and Rosenberg. Annex A Reconciliation of Non-GAAP Financial Measures (iii) (iv) (v) | ||||||||
