4.	Leases

The Company leases certain property, plant and equipment under operating leases, primarily consisting of railroad equipment leases. Net minimum future rental payments due under non-cancelable operating leases with remaining terms in excess of one year as of December 31, 2013 are as follows:


2014	$	14,655
2015		15,450
2016		16,150
2017		13,142
2018		11,247
Thereafter		38,196

Total	$	108,840

Leases of railroad equipment generally provide for renewal options at their fair rental value at the time of renewal. In the normal course of business, operating leases for railroad equipment are generally renewed or replaced by other leases. For the years ended December 31, 2014 and 2015, minimum future rental payments in the table above are presented net of sublease income related to subleases of railroad equipment of $1,985 and $1,619, respectively. Rent expense for all operating leases was $22,542 in 2013, $21,452 in 2012 and $11,590 in 2011. For the year ended December 31, 2013, rent expense is stated net of sublease income of $208.