Commitments

Leases

The future minimum obligations under operating leases having a noncancelable term in excess of one year as of December 31, 2017, are as follows:



2018	$	4.0
2019	2.6
2020	2.1
2021	1.8
2022	1.6
Thereafter	3.7
Future minimum lease obligations	$	15.8

For the years ended December 31, 2017, 2016 and 2015 rent expense under operating leases was $6.8 million, $6.4 million and $5.4 million, respectively.

Purchase Commitments

The Company has certain minimum purchase commitments that extend beyond December 31, 2017. Commitments under these contracts are approximately $12.3 million and $6.1 million for the years ended December 31, 2018 and 2019, respectively. Such purchase commitments for the year ended December 31, 2018 are primarily for coal and corn starch contracts. Although the Company is primarily liable for payments on the above-mentioned leases and purchase commitments, management believes exposure to losses, if any, under these arrangements is not material.