Leases (Tables)

12 Months Ended

Dec. 31, 2012

Leases [Abstract]

Schedule of Rent Expense

The Company and its subsidiaries currently lease various facilities and equipment under a number of cancelable and noncancelable operating leases. Lease agreements for barges have terms from one to 10 years expiring at various dates through 2021. Lease agreements for towing vessels chartered by the Company have terms from 30 days to five years expiring at various dates through 2016; however, the majority of the towing vessel charter agreements are for terms of one year or less. Total rental expense for the years ended December 31, 2012, 2011 and 2010 was as follows (in thousands):

	2012		2011		2010
Rental expense:
Marine equipment — barges	$	23,835	$	16,396	$	9,075
Marine equipment — towing vessels		97,428		91,796		79,016
Other buildings and equipment		9,952		8,156		5,334
Rental expense	$	131,215	$	116,348	$	93,425

Schedule of 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, 2012 were as follows (in thousands):

				Marine Equipment
		Land, Buildings and Equipment		Barges		Towing Vessels
2013	$	8,421	$	19,309	$	73,028	$	100,758
2014		7,372		17,125		44,011		68,508
2015		5,991		15,497		34,620		56,108
2016		3,191		11,984		3,137		18,312
2017		2,444		11,397		—		13,841
Thereafter		5,635		22,366		—		28,001
	$	33,054	$	97,678	$	154,796	$	285,528