v3.26.1
COMMITMENTS AND CONTINGENCIES - Narrative (Details) - USD ($)
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
COMMITMENTS AND CONTINGENCIES      
Unfunded capital commitments $ 1,518,700,000   $ 1,172,900,000
Maximum exposure from guarantees 7,000,000.0   7,100,000
Carried interest, contingent repayment obligations 0   0
Performance income      
COMMITMENTS AND CONTINGENCIES      
Performance income subject to potential clawback provision 115,300,000   125,600,000
Performance income subject to potential claw back provision that are reimbursable by professionals $ 90,700,000   99,800,000
Minimum      
COMMITMENTS AND CONTINGENCIES      
Service period 3 years    
Maximum      
COMMITMENTS AND CONTINGENCIES      
Service period 6 years    
Lease terms 17 years    
Accounts Payable and Accrued Liabilities      
COMMITMENTS AND CONTINGENCIES      
Contingent consideration $ 2,400,000   2,300,000
Remaining Contingent Earnout Arrangements | Other Operating Income (Expense)      
COMMITMENTS AND CONTINGENCIES      
Contingent arrangements, other expense 100,000 $ 100,000  
GCP International | DC Earnout      
COMMITMENTS AND CONTINGENCIES      
Maximum exposure from contingent arrangements 1,000,000,000.0    
GCP International | Japan Earnout      
COMMITMENTS AND CONTINGENCIES      
Maximum exposure from contingent arrangements $ 500,000,000    
GCP International | DC Earnout And Japan Earnout      
COMMITMENTS AND CONTINGENCIES      
Contingent consideration, liability, paid in cash (as a percent) 15.00%    
GCP International | DC Earnout And Japan Earnout | Other Operating Income (Expense)      
COMMITMENTS AND CONTINGENCIES      
Changes in value of contingent earnout arrangements $ 14,300,000    
GCP International | DC Earnout And Japan Earnout | Accounts Payable and Other Accrued Liabilities      
COMMITMENTS AND CONTINGENCIES      
Contingent consideration 777,300,000   763,000,000.0
GCP International | Earnout Arrangement And Management Incentive Program      
COMMITMENTS AND CONTINGENCIES      
Contingent arrangements, amount accrued 91,600,000   70,100,000
Deferred compensation expense 21,500,000 4,300,000  
GCP International | Earnout Arrangement And Management Incentive Program | Accrued Compensation      
COMMITMENTS AND CONTINGENCIES      
Contingent consideration 333,100,000   327,000,000.0
Other Arrangements      
COMMITMENTS AND CONTINGENCIES      
Maximum exposure from contingent arrangements 351,400,000   175,000,000.0
Contingent consideration 123,600,000   24,200,000
Contingent arrangements, amount accrued 14,300,000   $ 7,800,000
Other Arrangements | Remaining Contingent Earnout Arrangements      
COMMITMENTS AND CONTINGENCIES      
Compensation expense $ 6,500,000 $ 7,000,000.0