Impairments and Other Charges (Details)	3 Months Ended			12 Months Ended
	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) $ / shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) TankBarge
Impairments and Other Charges [Abstract]
Impairment charge	$ 165,304,000
Impairment of intangible assets other than goodwill	148,909,000
Impairment of property and equipment	16,395,000
Goodwill impairment charge	387,970,000		$ 2,702,000	$ 387,970,000		$ 2,702,000
Impairments and Other Charges [Abstract]
Non-cash pre-tax impairment charge	$ 8,000,000	$ 35,525,000	82,705,000
Impairment charge after tax effect			$ 65,337,000
Impairment charge after tax effect on earning per share (in dollars per share) | $ / shares			$ 1.09
Lease cancellation costs				$ 0	$ 0	2,403,000
Vessels [Member]
Impairments and Other Charges [Abstract]
Non-cash pre-tax impairment charge			$ 78,835,000
Fair market value of assets			13,247,000			13,247,000
Tank Barge [Member]
Impairments and Other Charges [Abstract]
Non-cash pre-tax impairment charge						$ 3,870,000
Number of vessels to be disposed of | TankBarge						4
Fair market value of assets			220,000			$ 220,000
Scrap value of vessel			$ 220,000			220,000
Lease cancellation costs						$ 2,403,000