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, 2014 are as follows:


2015	$	17,682
2016		20,369
2017		18,711
2018		16,370
2019		13,567
Thereafter		53,866

Total	$	140,565

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, 2015 and 2016, minimum future rental payments in the table above are presented net of sublease income related to subleases of railroad equipment of $4,007 and $2,242, respectively. Rent expense for all operating leases was $24,116 in 2014, $22,542 in 2013 and $21,452 in 2012. For the years ended December 31, 2014 and 2013, rent expense is stated net of sublease income of $1,816 and $208, respectively.