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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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STOCK-BASED COMPENSATION - Narrative (Details) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2026 USD ($) shares	Sep. 30, 2025 USD ($)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Percentage of aggregate number of shares			0.06
Total stock-based compensation expense	$ 3.5	$ 0.2	$ 8.8	$ 4.2
Share-based payment arrangement, nonvested award, cost not yet recognized, amount	30.4		30.4
Additional Paid in Capital \| GPGI Holdings
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares granted, value, share-based payment arrangement, after forfeiture	3.1	5.6	7.9	12.4
Contractor Agreements
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total stock-based compensation expense	3.1		7.8
Restricted stock unit expense
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total stock-based compensation expense	0.9	0.0	2.3	3.0
Unrecognized compensation	18.6		$ 18.6
Unrecognized compensation expense, period of recognition			5 years 7 months 6 days
Granted (in shares) \| shares			1.8
Performance stock unit expense
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total stock-based compensation expense	0.0	0.0	$ 0.0	0.5
Unrecognized compensation	0.0		$ 0.0
Granted (in shares) \| shares			0.0
Stock option expense
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total stock-based compensation expense	$ 2.6	$ 0.2	$ 6.5	$ 0.7
Unrecognized compensation expense, period of recognition			3 years 1 month 6 days
Long Term Incentive Plan Awards \| Husky
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Performance incentive program, EBITDA, duration	4 years		4 years
Performance incentive program, adjusted EBITDA, target award percentage	20.00%		20.00%
Performance incentive program, adjusted EBITDA, target award value			$ 10.0
Long Term Incentive Plan Awards \| Husky \| 2026 Target Husky Adjusted EBITDA
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Performance incentive program, adjusted EBITDA			500.0
Long Term Incentive Plan Awards \| Husky \| 2027 Target Husky Adjusted EBITDA
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Performance incentive program, adjusted EBITDA			575.0
Long Term Incentive Plan Awards \| Husky \| 2028 Target Husky Adjusted EBITDA
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Performance incentive program, adjusted EBITDA			660.0
Long Term Incentive Plan Awards \| Husky \| 2029 Target Husky Adjusted EBITDA
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Performance incentive program, adjusted EBITDA			$ 760.0