v3.26.3
Segment reporting - Schedule of reconciliation of profit (loss) by segment (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Segment Reporting [Line Items]        
Other non-cash items     $ (55.5) $ (20.5)
Other income (expense) - net $ 4.0 $ (3.3) 10.9 (1.8)
Interest expense and related financing costs - net (46.9) (34.9) (170.6) (84.9)
Income tax expense (41.5) (14.9) (58.8) (45.0)
Net income (loss) 109.2 39.5 83.3 136.9
Operating Segments        
Segment Reporting [Line Items]        
Total Adjusted Segment EBITDA 256.5 155.8 577.8 426.2
Management adjustments (2.2) (1.0) (4.3) (2.1)
Other non-cash items 2.5 2.3 8.0 6.0
Depreciation and amortization (26.2) (28.1) (78.5) (76.0)
Segment Reporting, Reconciling Item, Corporate Nonsegment        
Segment Reporting [Line Items]        
Unallocated corporate costs (HQ & other not included in Adjusted Segment EBITDA) (11.1) (11.6) (37.6) (24.0)
Segment reporting, reconciling item, excluding corporate nonsegment        
Segment Reporting [Line Items]        
Acquisition and Divestment related gains (losses) - net (1.7) (0.6) (2.4) (1.0)
Transaction costs (0.1) (0.1) (4.7) (0.1)
Transformation costs (2.0) (2.7) (7.3) (8.4)
IPO and Public market readiness costs (2.5) (4.8) (93.6) (4.9)
Share-based compensation (3.9) 0.0 (5.0) 0.0
Management adjustments (10.2) (8.2) (113.0) (14.4)
Other non-cash items (2.5) (2.3) (8.0) (6.0)
Depreciation and amortization (39.1) (41.1) (117.4) (113.2)
Other income (expense) - net 4.0 (3.3) 10.9 (1.8)
Interest expense and related financing costs - net (46.9) (34.9) (170.6) (84.9)
Income tax expense $ (41.5) $ (14.9) $ (58.8) $ (45.0)