21. Commitments and Contingencies Leases The Company is obligated under certain operating leases and rental agreements for railroad cars, office space, and other equipment. Future minimum annual commitments under such operating leases at December31, 2016 are as follows: Twelve months ending December 31, 2017 $ 6,576 2018 5,173 2019 4,052 2020 3,038 2021 2,247 Thereafter 338 Expense related to operating leases and rental agreements was $7,065, $4,098 and $2,530 for the years ended December31, 2016, 2015 and 2014, respectively. Lease expense related to rail cars are included in cost of goods sold in the consolidated statement of operations. Litigation The Company is periodically involved in litigation and claims incidental to its operation. Other than the below, management believes that any pending litigation will not have a material impact the Companys financial position. In August 2016, an affiliate of one of the Companys customers, in conjunction with bankruptcy proceedings, demanded a refund of the remaining balance of prepayments it claimed to have made pursuant to the agreement with the Companys customer. In November 2016, this was settled favorably for the Company; accordingly, the full amount of the prepayment was recognized as revenue. As part of this settlement, the Company was granted an unsecured bankruptcy claim of approximately $12 million; in December 2016, a third party purchased the Companys unsecured claim for approximately $6.6 million which was recognized in other income in the fourth quarter. Employment Agreements Certain of the Companys executives are employed under employment agreements, the terms of which provide for, among other things, a base salary plus additional compensation including an annual bonus based on the percentage as defined and agreed upon by the Board based on service and/or performance in a given calendar year. The agreements, which contain one-year automatic renewals, provide for benefits that are customary for senior-level employees. The Company is required to pay