Leases (Tables)

12 Months Ended

Dec. 31, 2018

Total rental expense for the years ended December 31, 2018, 2017 and 2016 was as follows (in thousands):

	2018		2017		2016
Rental expense:
Marine equipment — barges	$	10,234	$	11,550	$	13,791
Marine equipment — towing vessels		140,389		116,690		137,609
Other buildings and equipment		23,365		15,915		11,182
Rental expense	$	173,988	$	144,155	$	162,582

Future Minimum Lease Payments under Operating Leases

Future minimum lease payments under operating leases that have initial or remaining noncancelable lease terms in excess of one year at December 31, 2018 were as follows (in thousands):

	Land, Buildings		Marine Equipment
	And Equipment		Barges		Towing Vessels		Total
2019	$	19,524	$	6,808	$	70,759	$	97,091
2020		16,916		5,400		7,746		30,062
2021		15,112		4,128		2,578		21,818
2022		13,547		4,138		2,578		20,263
2023		11,821		3,030		2,578		17,429
Thereafter		75,818		7,098		9,023		91,939
	$	152,738	$	30,602	$	95,262	$	278,602