Impairments and Other Charges - Summary of Changes in Goodwill (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Mar. 31, 2020	Sep. 30, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Balance	$ 1,065,939,000		$ 1,065,939,000	$ 1,065,939,000
Accumulated impairment and amortization	627,191,000		627,191,000	408,139,000
Impairment		$ 387,970,000	219,052,000
Balance	438,748,000		438,748,000	657,800,000
Marine Transportation [Member]
Goodwill [Roll Forward]
Balance	505,784,000		505,784,000	505,784,000
Accumulated impairment and amortization	237,626,000		237,626,000	18,574,000
Impairment	219,052,000		219,052,000
Balance	268,158,000		268,158,000	487,210,000
Distribution And Services [Member]
Goodwill [Roll Forward]
Balance	560,155,000		560,155,000	560,155,000
Accumulated impairment and amortization	389,565,000		389,565,000	389,565,000
Impairment
Balance	$ 170,590,000		$ 170,590,000	$ 170,590,000