COMMITMENTS AND CONTINGENCIES - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Mar. 01, 2025
COMMITMENTS AND CONTINGENCIES
Unfunded capital commitments	$ 1,172,900,000	$ 1,451,400,000
Maximum exposure from guarantees	7,100,000	1,100,000
Carried interest, contingent repayment obligations	0	0
Performance income
COMMITMENTS AND CONTINGENCIES
Performance income subject to potential clawback provision	125,600,000	59,600,000
Performance income subject to potential claw back provision that are reimbursable by professionals	$ 99,800,000	39,500,000
Minimum
COMMITMENTS AND CONTINGENCIES
Service period	3 years
Maximum
COMMITMENTS AND CONTINGENCIES
Service period	6 years
Lease terms	18 years
Accounts Payable and Accrued Liabilities
COMMITMENTS AND CONTINGENCIES
Contingent consideration	$ 2,300,000	2,100,000
Remaining Contingent Earnout Arrangements | Other Operating Income (Expense)
COMMITMENTS AND CONTINGENCIES
Contingent arrangements, other expense	200,000
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	$ 298,000,000.0
GCP International | DC Earnout And Japan Earnout | Due to Affiliates
COMMITMENTS AND CONTINGENCIES
Contingent consideration				$ 465,100,000
GCP International | DC Earnout And Japan Earnout | Accounts Payable and Other Accrued Liabilities
COMMITMENTS AND CONTINGENCIES
Contingent consideration	763,000,000.0
GCP International | Earnout Arrangement And Management Incentive Program
COMMITMENTS AND CONTINGENCIES
Deferred compensation expense	70,100,000
GCP International | Earnout Arrangement And Management Incentive Program | Accrued Compensation
COMMITMENTS AND CONTINGENCIES
Contingent consideration	327,000,000.0
Other Arrangements
COMMITMENTS AND CONTINGENCIES
Maximum exposure from contingent arrangements	175,000,000.0	115,000,000.0
Contingent consideration	24,200,000	88,900,000
Contingent arrangements, amount accrued	7,800,000	29,300,000
Consideration, compensation reversal due to change in estimate	25,000,000.0
Other Arrangements | Settled Contingent Earnout Arrangement
COMMITMENTS AND CONTINGENCIES
Contingent consideration		31,100,000
Payment for contingent consideration liability	26,000,000.0
Compensation expense	8,000,000.0	600,000
Contingent arrangements, other expense	2,900,000
Other Arrangements | Remaining Contingent Earnout Arrangements
COMMITMENTS AND CONTINGENCIES
Compensation expense	$ (21,500,000)	$ 21,500,000	$ 6,500,000