FAIR VALUE MEASUREMENTS - Schedule of Fair Value Measurements (Details) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Contingent consideration liability | $ 13.4 | $ 13.4 |
Discretionary investments | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
T. Rowe Price investment products | 259.9 | 246.4 |
Seed capital | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
T. Rowe Price investment products | 237.7 | 247.8 |
Supplemental savings plan liability economic hedges | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
T. Rowe Price investment products | 837.4 | 806.6 |
Level 1 | Fair value, measurements, recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents held in money market funds | 1,997.4 | 1,678.1 |
Other investments | 0.6 | 0.7 |
Investments in affiliated collateralized loan obligations | 0 | 0 |
Total | 3,282.3 | 2,937.8 |
Contingent consideration liability | 0 | 0 |
Level 1 | Fair value, measurements, recurring | Discretionary investments | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
T. Rowe Price investment products | 259.9 | 246.4 |
Level 1 | Fair value, measurements, recurring | Seed capital | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
T. Rowe Price investment products | 187 | 206 |
Level 1 | Fair value, measurements, recurring | Supplemental savings plan liability economic hedges | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
T. Rowe Price investment products | 837.4 | 806.6 |
Level 2 | Fair value, measurements, recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents held in money market funds | 0 | 0 |
Other investments | 0 | 0 |
Investments in affiliated collateralized loan obligations | 7.9 | 8.4 |
Total | 58.6 | 50.2 |
Contingent consideration liability | 0 | 0 |
Level 2 | Fair value, measurements, recurring | Discretionary investments | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
T. Rowe Price investment products | 0 | 0 |
Level 2 | Fair value, measurements, recurring | Seed capital | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
T. Rowe Price investment products | 50.7 | 41.8 |
Level 2 | Fair value, measurements, recurring | Supplemental savings plan liability economic hedges | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
T. Rowe Price investment products | 0 | 0 |
Level 3 | Fair value, measurements, recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash equivalents held in money market funds | 0 | 0 |
Other investments | 0 | 0 |
Investments in affiliated collateralized loan obligations | 0 | 0 |
Total | 0 | 0 |
Contingent consideration liability | 13.4 | 13.4 |
Level 3 | Fair value, measurements, recurring | Discretionary investments | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
T. Rowe Price investment products | 0 | 0 |
Level 3 | Fair value, measurements, recurring | Seed capital | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
T. Rowe Price investment products | 0 | 0 |
Level 3 | Fair value, measurements, recurring | Supplemental savings plan liability economic hedges | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
T. Rowe Price investment products | $ 0 | $ 0 |