GENERAL SIGNIFICANT ACCOUNTING POLICIES - CAPITAL CONSTRUCTION FUND (Details) $ in Millions	6 Months Ended
	Jun. 30, 2023 USD ($) item	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Cash deposits	$ 113.1	$ 10.7
Qualifying cash withdrawal payments	49.9	10.7
Accounts receivable, net	$ 285.0		$ 268.5
Number of vessels under agreements for construction | item	3
Eligible Accounts Receivable Assigned to CCF
Capital construction fund	$ 583.9		518.2
Cash deposits	100.0	10.7
Interest earned	15.6
Qualifying cash withdrawal payments	(49.9)	(10.7)
Amount pledged to capital construction fund	200.0	$ 0.0
Accounts receivable, net	$ 210.0		$ 9.9
Weighted average life of securities held within the fund	41 days