COMMITMENTS AND CONTINGENCIES

Commitments

The Company leases certain buildings and equipment. The Company's facility and equipment leases may provide for escalations of rent or rent abatements and payment of pro rata portions of building operating expenses. Minimum lease payments are recognized on a straight-line basis over the minimum lease term. The total expenses under operating leases for the three and nine months ended September 30, 2018 were $0.6 million and $2.2 million, respectively, compared to $0.8 million and $2.5 million for the same periods in 2017, respectively. The Company also has non-capital purchase commitments that primarily relate to gas, gypsum, paper and other raw materials. The total amounts purchased under such commitments were $22.7 million and $69.5 million for the three and nine months ended September 30, 2018, respectively, compared to $22.0 million and $64.8 million for the three and nine months ended September 30, 2017, respectively.



Table 16: Details of Future Minimum Lease Payments Due Under Noncancellable Operating Leases and Purchase Commitments
	Future Minimum Lease Payments		Purchase Commitments
	(in thousands)
October 1, 2018 - December 31, 2018	$	180	$	17,958
2019	1,658		47,287
2020	48		46,141
2021	—		28,097
2022	—		25,069
2023	—		12,284
Thereafter	—		53,621
Total	$	1,886	$	230,457

Contingent obligations

Under certain circumstances, the Company provides letters of credit related to its natural gas and other supply purchases. As of September 30, 2018 and December 31, 2017, the Company had outstanding letters of credit of approximately $1.4 million.

Legal Matters

In the ordinary course of business, the Company executes contracts involving indemnifications standard in the industry. These indemnifications might include claims relating to any of the following: environmental and tax matters; intellectual property rights; governmental regulations and employment-related matters; customer, supplier, and other commercial contractual relationships; and financial matters. While the maximum amount to which the Company may be exposed under such agreements cannot be estimated, it is the opinion of management that these guarantees and indemnifications are not expected to have a material adverse effect on the Company's financial condition, results of operations or liquidity.

In the ordinary course of business, the Company is involved in certain legal actions and claims, including proceedings under laws and regulations relating to environmental and other matters. Because such matters are subject to many uncertainties and the outcomes are not predictable with assurance, the total liability for these legal actions and claims cannot be determined with certainty. When the Company determines that it is probable that a liability for environmental matters, legal actions or other contingencies has been incurred and the amount of the loss is reasonably estimable, an estimate of the costs to be incurred is recorded as a liability in the financial statements. As of September 30, 2018 and December 31, 2017, such liabilities were not expected to have a material adverse effect on the Company's financial condition, results of operations or liquidity. While management believes its accruals for such liabilities are adequate, the Company may incur costs in excess of the amounts provided. Although the ultimate amount of liability that may result from these matters or actions is not ascertainable, any amounts exceeding the recorded accruals are not expected to have a material adverse effect on the Company's financial condition, results of operations or liquidity.