REPORTABLE SEGMENTS (Details) $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($) segment customer	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Segment results
Number of segments | segment	2
Total Operating Revenue	$ 3,344.5	$ 3,421.8	$ 3,094.6
Operating costs:
Direct cargo expense	(999.3)	(980.1)	(946.2)
Vessel operating expense	(593.8)	(610.5)	(580.4)
Operating overhead	(329.1)	(329.1)	(297.7)
Direct operating costs	(494.0)	(493.1)	(504.2)
Depreciation and amortization	(166.9)	(153.1)	(142.2)
Total operating costs	(2,583.1)	(2,565.9)	(2,470.7)
Income (Loss) from SSAT	32.5	(1.0)	2.2
General and administrative	(294.1)	(303.6)	(283.3)
Total Costs and Expenses	(2,844.7)	(2,870.5)	(2,751.8)
Operating Income	499.8	551.3	342.8
Interest income	31.7	48.3	36.0
Interest expense	(6.8)	(7.5)	(12.2)
Other income (expense), net	9.1	7.3	6.4
Income before Taxes	533.8	599.4	373.0
Income taxes	(89.0)	(123.0)	(75.9)
Net Income	444.8	476.4	297.1
Capital Expenditures	393.4	310.1	248.4
Capital expenditures included in accounts payable, accruals and other liabilities	2.3	7.9	10.8
Operating segments
Segment results
Total Operating Revenue	3,344.5	3,421.8	3,094.6
Intersegment Eliminations
Segment results
Total Operating Revenue	237.1	245.8	208.7
Ocean Transportation
Operating costs:
Direct cargo expense	(999.3)	(980.1)	(946.2)
Vessel operating expense	(593.8)	(610.5)	(580.4)
Operating overhead	(329.1)	(329.1)	(297.7)
Depreciation and amortization	(154.0)	(141.1)	(130.6)
Total operating costs	(2,076.2)	(2,060.8)	(1,954.9)
Income (Loss) from SSAT	32.5	(1.0)	2.2
General and administrative	(236.2)	(247.0)	(229.5)
Total Costs and Expenses	(2,279.9)	(2,308.8)	(2,182.2)
Operating Income	455.6	500.9	294.8
Capital Expenditures	386.1	298.9	240.2
Dry-docking amortization	$ 28.9	27.2	25.3
Ocean Transportation | Revenue | Serves customers
Operating costs:
Transportation customers | customer	10
Concentration percentage	19.00%
Ocean Transportation | Operating segments
Segment results
Total Operating Revenue	$ 2,735.5	2,809.7	2,477.0
Ocean Transportation | Intersegment Eliminations
Segment results
Total Operating Revenue	92.5	92.8	76.5
Logistics
Operating costs:
Direct operating costs	(494.0)	(493.1)	(504.2)
Depreciation and amortization	(12.9)	(12.0)	(11.6)
Total operating costs	(506.9)	(505.1)	(515.8)
General and administrative	(57.9)	(56.6)	(53.8)
Total Costs and Expenses	(564.8)	(561.7)	(569.6)
Operating Income	44.2	50.4	48.0
Capital Expenditures	$ 7.3	11.2	8.2
Logistics | Revenue | Serves customers
Operating costs:
Transportation customers | customer	10
Concentration percentage	17.00%
Logistics | Operating segments
Segment results
Total Operating Revenue	$ 609.0	612.1	617.6
Logistics | Intersegment Eliminations
Segment results
Total Operating Revenue	$ 144.6	$ 153.0	$ 132.2