Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash Flows From Operating Activities:
Net income	$ 927.4	$ 193.1	$ 82.7
Reconciling adjustments:
Depreciation and amortization	135.9	114.9	100.4
Amortization of operating lease right of use assets	103.3	74.8	60.7
Deferred income taxes	33.2	52.1	23.6
(Gain) Loss on disposal of property and equipment	(0.8)	2.8	(1.4)
Share-based compensation expense	19.3	18.8	11.3
Income from SSAT	(56.3)	(26.3)	(20.8)
Distributions from SSAT	46.9	55.4	25.2
Changes in assets and liabilities:
Accounts receivable, net	(90.3)	(48.0)	17.8
Deferred dry-docking payments	(36.3)	(16.8)	(25.9)
Deferred dry-docking amortization	24.3	25.1	34.3
Prepaid expenses and other assets	(48.1)	21.9	24.5
Accounts payable, accruals and other liabilities	39.6	44.8	(13.9)
Operating lease liabilities	(99.7)	(75.9)	(59.9)
Other long-term liabilities	(14.3)	(6.9)	(9.8)
Net cash provided by operating activities	984.1	429.8	248.8
Cash Flows From Investing Activities:
Capitalized vessel construction expenditures	(14.9)	(87.8)	(219.1)
Other capital expenditures	(310.4)	(104.5)	(91.2)
Proceeds from disposal of property and equipment	1.9	15.3	3.4
Cash deposits into Capital Construction Fund	(31.2)	(132.4)	(96.2)
Withdrawals from Capital Construction Fund	31.2	132.4	96.2
Net cash used in investing activities	(323.4)	(177.0)	(306.9)
Cash Flows From Financing Activities:
Proceeds from issuance of debt		325.5
Repayments of debt	(59.3)	(216.5)	(42.1)
Proceeds from revolving credit facility	304.3	648.0	622.1
Repayments of revolving credit facility	(376.1)	(955.3)	(478.0)
Payment of financing costs	(3.0)	(18.5)
Proceeds from issuance of common stock		0.1	0.3
Dividends paid	(45.9)	(39.2)	(37.2)
Repurchase of Matson common stock	(198.3)
Tax withholding related to net share settlements of restricted stock units	(14.4)	(5.6)	(3.1)
Net cash (used in) provided by financing activities	(392.7)	(261.5)	62.0
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	268.0	(8.7)	3.9
Cash, Cash Equivalents and Restricted Cash, Beginning of the Year	19.7	28.4	24.5
Cash, Cash Equivalents and Restricted Cash, End of the Year	287.7	19.7	28.4
Reconciliation of Cash, Cash Equivalents, and Restricted Cash, at End of the Year:
Cash and Cash Equivalents	282.4	14.4	21.2
Restricted Cash	5.3	5.3	7.2
Total Cash, Cash Equivalents and Restricted Cash, End of the Year	287.7	19.7	28.4
Supplemental Cash Flow Information:
Interest paid, net of capitalized interest	19.3	26.2	22.0
Income tax paid, net of income tax refunds	241.6	(16.1)	(24.2)
Non-cash Information:
Capital expenditures included in accounts payable, accruals and other liabilities	$ 6.4	$ 24.7	$ 8.5