Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Flows From Operating Activities:
Net income	$ 82.7	$ 109.0	$ 231.0
Reconciling adjustments:
Depreciation and amortization	100.4	94.4	101.2
Amortization of operating lease right of use assets	60.7
Deferred income taxes	23.6	29.3	(127.9)
Loss (gain) on disposal of property and equipment	(1.4)	(1.9)	3.0
Share-based compensation expense	11.3	12.1	11.1
Income from SSAT	(20.8)	(36.8)	(28.2)
Distribution from SSAT	25.2	42.0	17.5
Changes in assets and liabilities:
Accounts receivable, net	17.8	(29.1)	(5.1)
Deferred dry-docking payments	(25.9)	(19.2)	(54.6)
Deferred dry-docking amortization	34.3	37.4	46.2
Prepaid expenses and other assets	24.5	4.2	14.4
Accounts payable, accruals and other liabilities	(13.9)	71.2	20.4
Operating lease liabilities	(59.9)
Other long-term liabilities	(9.8)	(7.6)	(4.1)
Net cash provided by operating activities	248.8	305.0	224.9
Cash Flows From Investing Activities:
Capitalized vessel construction expenditures	(219.1)	(338.6)	(252.0)
Other capital expenditures	(91.2)	(62.6)	(55.0)
Proceeds from (payments for) disposal of property and equipment	3.4	136.3	(0.2)
Cash deposits into Capital Construction Fund	(96.2)	(340.0)	(171.4)
Withdrawals from Capital Construction Fund	96.2	340.9	201.7
Proceeds from sale of other investments		3.7
Net cash used in investing activities	(306.9)	(260.3)	(276.9)
Cash Flows From Financing Activities:
Repayments of debt	(42.0)	(30.0)	(30.0)
Repayment of capital leases		(0.7)	(1.8)
Repayment of capital leases	(0.1)
Proceeds from revolving credit facility	622.1	963.9	469.0
Repayments of revolving credit facility	(478.0)	(933.9)	(319.0)
Payment of financing costs			(1.7)
Proceeds from issuance of common stock	0.3	0.7	1.9
Dividends paid	(37.2)	(35.4)	(33.8)
Repurchase of Matson common stock			(19.3)
Tax withholding related to net share settlements of restricted stock units	(3.1)	(4.6)	(7.4)
Net cash provided by (used in) financing activities	62.0	(40.0)	57.9
Net Increase in Cash, Cash Equivalents and Restricted Cash	3.9	4.7	5.9
Cash, Cash Equivalents and Restricted Cash, Beginning of the Year	24.5	19.8	13.9
Cash, Cash Equivalents and Restricted Cash, End of the Year	28.4	24.5	19.8
Reconciliation of Cash, Cash Equivalents, and Restricted Cash, at End of the Year:
Cash and Cash Equivalents	21.2	19.6	19.8
Restricted Cash	7.2	4.9
Cash, Cash Equivalents and Restricted Cash, End of the Year	28.4	24.5	19.8
Supplemental Cash Flow Information:
Interest paid, net of capitalized interest	22.0	18.3	23.9
Income tax paid, net of income tax refunds	(24.2)	5.2	2.6
Non-cash Information:
Capital expenditures included in accounts payable, accruals and other liabilities	$ 8.5	$ 4.1	$ 1.2