Our operations and properties are subject to extensive and changing federal, state, and local laws; regulations and ordinances governing the protection of the environment; as well as laws relating to worker health and workplace safety. We carefully consider the requirements mandated by such laws and regulations and have procedures in place at all of our operating units to monitor compliance. Any matters which are identified as potential exposures under these laws and regulations are carefully reviewed by management to determine our potential liability. Although management is not aware of any exposures which require an accrual under generally accepted accounting principles, there can be no assurance that prior or future operations will not ultimately result in violations, claims, or other liabilities associated with these regulations.

We have certain deductible limits under our workers’ compensation and liability insurance policies for which reserves are established based on the undiscounted estimated costs of known and anticipated claims. We have entered into standby letter of credit agreements relating to workers’ compensation and auto and general liability self-insurance. At March 31, 2019, we had contingent liabilities under these outstanding letters of credit of approximately $7.7 million.

We are currently contingently liable for performance under $26.3 million in performance bonds required by certain states and municipalities, and their related agencies. The bonds are principally for certain reclamation obligations and mining permits. We have indemnified the underwriting insurance company against any exposure under the performance bonds. In our past experience, no material claims have been made against these financial instruments.

Since late December 2012, several purported class action lawsuits were filed in various federal district courts, against the Company’s subsidiary, American Gypsum Company LLC (American Gypsum) and other wallboard manufacturers, alleging that the defendant wallboard manufacturers conspired to fix the price for drywall sold in the United States in violation of federal antitrust laws and, in some cases, related provisions of state law. The Company and American Gypsum denied all allegations that they conspired to increase the price of drywall and asserted affirmative defenses to the plaintiffs’ claims.

On December 29, 2017, American Gypsum and the Company, entered into a settlement agreement (the Direct Purchaser Settlement Agreement) with counsel representing the direct purchaser class to settle all claims made against the Company, American Gypsum, and other manufacturers in the direct purchaser class action. The Direct Purchaser Settlement Agreement, in which the Company and American Gypsum deny all wrongdoing, also includes releases by the participating class members of the Company and American Gypsum as well as their subsidiaries, affiliates, and other related parties, for the time period from January 1, 2012 through the date of execution of the Direct Purchaser Settlement Agreement. On January 5, 2018, American Gypsum entered into a settlement agreement (the Indirect Purchaser Settlement Agreement) with counsel representing the indirect purchaser class to settle all claims against American Gypsum and the other manufacturers in the indirect purchaser class action. Under the Direct and Indirect Purchaser Settlement Agreements, the Company and American Gypsum agreed to pay a total of approximately $39.1 million in cash to settle the claims against them. These claims were accrued during March 2018, and we deposited approximately $38.8 million into a qualified settlement fund. The amount accrued under the Direct Purchaser Settlement Agreement was paid in July 2018 after approval by the District Court.

In March 2015, a group of homebuilders filed a complaint against the defendants, including American Gypsum, based upon the same conduct alleged in the consolidated class action complaints. Effective May 8, 2018, American Gypsum and the homebuilder plaintiffs entered into a settlement agreement (the Homebuilder Settlement Agreement) to settle all claims made against American Gypsum. The Homebuilder Settlement Agreement, in which American Gypsum denies all wrongdoing, includes releases by the homebuilder plaintiffs of American Gypsum as well as its subsidiaries, affiliates, and other related parties, for the time period prior to and including the date of execution of the Homebuilder Settlement Agreement. Under the Homebuilder Settlement Agreement, American Gypsum agreed to pay a total of $6.0 million in cash to settle the claims against it. At March 31, 2018, we accrued the total amount of this settlement, and this amount was paid in May 2018.

In June 2015, American Gypsum and an employee received grand jury subpoenas from the United States District Court for the Western District of North Carolina seeking information regarding an investigation of the gypsum drywall industry by the Antitrust Division of the Department of Justice. We believe the investigation, although a separate proceeding, was related to the same subject matter at issue in the litigation described above. On August 24, 2018, the Antitrust Division notified us that the investigation had been closed.

In the ordinary course of business, we execute contracts involving indemnifications that are standard in the industry and indemnifications specific to a transaction such as the sale of a business. 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, construction contractor, and other commercial contractual relationships; and financial matters. While the maximum amount to which we may be exposed under such agreements cannot be estimated, it is the opinion of management that these indemnifications are not expected to have a material adverse effect on the Company’s consolidated financial position, results of operations, or cash flows. We currently have no outstanding guarantees of third-party debt.

We have certain forward purchase contracts, primarily for natural gas, that expire during calendar 2019 and 2020. The contracts are for approximately 25% of our anticipated natural gas usage.

We have certain operating leases covering manufacturing, transportation, a quarry and certain other facilities and equipment. Rental expense for fiscal years 2019, 2018, and 2017 totaled $12.3 million, $12.0 million and $11.3 million, respectively. Minimum annual rental commitments as of March 31, 2019, under noncancelable leases are set forth as follows (dollars in thousands):

Fiscal Year	Amount
2020	$	14,613
2021	$	11,487
2022	$	9,979
2023	$	9,784
2024	$	8,347
Thereafter	$	24,793