GOODWILL AND INTANGIBLE ASSETS - INTANGIBLE ASSETS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Intangible assets
Gross Amount	$ 274.5	$ 274.1
Less: Accumulated Amortization	(127.9)	(114.7)
Total Intangible Assets, net	146.6	159.4
Amortization expense	13.2	12.8	$ 13.6
Total amortization expense	$ 119.3
Customer Relationships | Maximum
Intangible assets
Expected useful life	21 years
Ocean Transportation | Customer Relationships
Intangible assets
Gross Amount	$ 140.6	140.6
Less: Accumulated Amortization	(71.0)	(64.4)
Total Intangible Assets, net	$ 69.6	76.2
Ocean Transportation | Customer Relationships | Horizon
Intangible assets
Expected useful life	21 years
Finite-Lived intangible assets acquired	$ 140.6
Logistics
Intangible assets
Gross Amount	133.9	133.5
Less: Accumulated Amortization	(56.9)	(50.3)
Total Intangible Assets, net	77.0	83.2
Logistics | Trade name - Logistics
Intangible assets
Indefinite-Lived intangible asset	27.3	27.3
Logistics | Span Alaska | Trade name - Logistics
Intangible assets
Indefinite-Lived intangible asset acquired	27.3
Logistics | Customer Relationships
Intangible assets
Gross Amount	106.6	106.2
Less: Accumulated Amortization	(56.9)	(50.3)
Total Intangible Assets, net	$ 49.7	$ 55.9
Logistics | Customer Relationships | Minimum
Intangible assets
Expected useful life	3 years
Logistics | Customer Relationships | Maximum
Intangible assets
Expected useful life	13 years
Logistics | Customer Relationships | Span Alaska
Intangible assets
Total Intangible Assets, net	$ 79.3
Expected useful life	20 years