CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
CONDENSED CONSOLIDATED BALANCE SHEETS [Abstract]
Unbilled voyage receivable (in dollars)	$ 238,212	$ 279,567
Voyage receivables, allowance for credit losses	123	261
Vessels and other property, accumulated depreciation	$ 353,314	$ 331,903
Common stock, shares authorized	100,000,000	100,000,000
Common stock, no par value	$ 0	$ 0
Common stock, shares, issued	49,171,314	49,120,648
Common stock, shares, outstanding	49,171,314	49,120,648