Acquisitions, 2020 (Details) $ in Thousands, MMBbls in Millions			3 Months Ended	12 Months Ended
	Mar. 31, 2020 USD ($) MMBbls Vessel	Jan. 03, 2020 USD ($)	Dec. 31, 2020 USD ($) Vessel	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) Vessel	Dec. 31, 2020 USD ($) Vessel
Acquisitions [Abstract]
Cash paid for acquisition				$ 172,606	$ 98,015	$ 148,185
Fair values of assets acquired and liabilities assumed, net [Abstract]
Goodwill			$ 657,800	$ 438,748	$ 438,748	$ 657,800
Inland Pressure Barges [Member]
Acquisitions [Abstract]
Number of maritime vessels acquired | Vessel			6			6
Cash paid for acquisition						$ 39,400
Inland Tank Barges [Member]
Acquisitions [Abstract]
Number of maritime vessels acquired | Vessel					4
Cash paid for acquisition					$ 7,500
Savage Inland Marine, LLC [Member]
Acquisitions [Abstract]
Cash paid for acquisition	$ 279,000
Fair values of assets acquired and liabilities assumed, net [Abstract]
Accounts receivable	0
Inventories	0
Prepaid expenses	1,067
Property and equipment	210,065
Operating lease right-of-use assets	27,085
Goodwill	81,635
Other intangibles	2,300
Total assets	322,152
Accounts payable and accrued liabilities	68
Operating lease liabilities, including current portion	43,085
Total liabilities	43,153
Net assets acquired	278,999
Acquisition related costs			$ 400
Savage Inland Marine, LLC [Member] | Customer Relationships [Member]
Fair values of assets acquired and liabilities assumed, net [Abstract]
Other intangibles	$ 2,300
Intangible assets amortization period						10 years
Savage Inland Marine, LLC [Member] | Inland Tank Barges [Member]
Acquisitions [Abstract]
Number of maritime vessels acquired | Vessel	92
Tank barge barrel capacity (in barrels) | MMBbls	2.5
Savage Inland Marine, LLC [Member] | Inland Towboats [Member]
Acquisitions [Abstract]
Number of maritime vessels acquired | Vessel	45
Convoy [Member]
Acquisitions [Abstract]
Cash paid for acquisition		$ 37,200
Fair values of assets acquired and liabilities assumed, net [Abstract]
Accounts receivable		5,677
Inventories		11,771
Prepaid expenses		177
Property and equipment		415
Operating lease right-of-use assets		3,713
Goodwill		10,309
Other intangibles		17,170
Total assets		49,232
Accounts payable and accrued liabilities		8,339
Operating lease liabilities, including current portion		3,713
Total liabilities		12,052
Net assets acquired		37,180
Weighted average amortization period of intangibles						11 years
Convoy [Member] | Customer Relationships [Member]
Fair values of assets acquired and liabilities assumed, net [Abstract]
Other intangibles		9,000
Intangible assets amortization period						10 years
Convoy [Member] | Distributorships [Member]
Fair values of assets acquired and liabilities assumed, net [Abstract]
Other intangibles		8,000
Intangible assets amortization period						12 years
Convoy [Member] | Non-compete Agreements [Member]
Fair values of assets acquired and liabilities assumed, net [Abstract]
Other intangibles		$ 200
Intangible assets amortization period						3 years