Commitments and Contingencies:

In the ordinary course of business, we have commitments in connection with various activities. We believe that amounts recorded are adequate for known items which might become due in the current year. The most significant commitments are as follows:

Environmental

We had the following activity in our recorded environmental liabilities for the years ended December 31, 2017, 2016 and 2015 (in thousands):



	Year Ended December 31,
	2017			2016			2015
Balance, beginning of year	$	34,919		$	31,436		$	9,235
Expenditures	(1,818		)	(2,667		)	(4,039		)
Acquisition of Rockwood	—			—			34,626
Divestitures	—			—			(1,826		)
Accretion of discount	896			793			902
Additions and revisions of estimates	3,344			4,004			150
Reclass to liabilities held for sale^(a)	—			—			(5,253		)
Foreign currency translation adjustments and other	2,467			1,353			(2,359		)
Balance, end of year	39,808			34,919			31,436
Less amounts reported in Accrued expenses	2,290			2,324			1,443
Amounts reported in Other noncurrent liabilities	$	37,518		$	32,595		$	29,993


(a)	Represents environmental liabilities of the metal sulfides and minerals-based flame retardants and specialty chemicals businesses. See Note 3, “Divestitures,” for additional information.

Environmental remediation liabilities included discounted liabilities of $28.1 million and $22.8 million at December 31, 2017 and 2016, respectively, discounted at rates with a weighted-average of 3.6% and 3.5%, respectively, with the undiscounted amount totaling $68.2 million and $61.1 million at December 31, 2017 and 2016, respectively. For certain locations where the Company is operating groundwater monitoring and/or remediation systems, prior owners or insurers have assumed all or most of the responsibility.

The amounts recorded represent our future remediation and other anticipated environmental liabilities. These liabilities typically arise during the normal course of our operational and environmental management activities or at the time of acquisition of the site, and are based on internal analysis as well as input from outside consultants. As evaluations proceed at each relevant site, changes in risk assessment practices, remediation techniques and regulatory requirements can occur, therefore such liability estimates may be adjusted accordingly. The timing and duration of remediation activities at these sites will be determined when evaluations are completed. Although it is difficult to quantify the potential financial impact of these remediation liabilities, management estimates (based on the latest available information) that there is a reasonable possibility that future environmental remediation costs associated with our past operations, in excess of amounts already recorded, could be up to approximately $18 million before income taxes.

We believe that any sum we may be required to pay in connection with environmental remediation matters in excess of the amounts recorded would likely occur over a period of time and would likely not have a material adverse effect upon our results of operations, financial condition or cash flows on a consolidated annual basis although any such sum could have a material adverse impact on our results of operations, financial condition or cash flows in a particular quarterly reporting period.

Asset Retirement Obligations

The following is a reconciliation of our beginning and ending asset retirement obligation balances for 2017 and 2016 (in thousands):



	Year Ended December 31,
	2017			2016
Balance, beginning of year	$	36,296		$	37,230
Additions and revisions of estimates	3,859			—
Accretion of discount	1,532			1,354
Liabilities settled	(789		)	(370		)
Foreign currency translation adjustments and other	(448		)	(1,918		)
Balance, end of year	$	40,450		$	36,296

Our asset retirement obligations are recorded in Other noncurrent liabilities in the consolidated balance sheets. Asset retirement obligations primarily relate to post-closure reclamation of brine wells and sites involved in the surface mining and manufacturing of lithium. We are not aware of any conditional asset retirement obligations that would require recognition in our consolidated financial statements.

Rental Expense

Our rental expenses include a number of operating lease agreements, primarily for office space, transportation equipment and storage facilities. The following schedule details the future non-cancelable minimum lease payments for the next five years and thereafter (in thousands):



	Operating Leases
2018	$	27,576
2019	$	25,609
2020	$	24,184
2021	$	23,722
2022	$	21,476
Thereafter	$	20,220

Rental expense was approximately $31.2 million, $31.4 million, and $34.8 million for 2017, 2016 and 2015, respectively. Rental expense related to discontinued operations was approximately $11.8 million and $10.2 million for 2016 and 2015, respectively. Rental expense is shown net of sublease income which was minimal during 2017, 2016 and 2015.

Litigation

We are involved from time to time in legal proceedings of types regarded as common in our business, including administrative or judicial proceedings seeking remediation under environmental laws, such as the federal Comprehensive Environmental Response, Compensation and Liability Act, commonly known as CERCLA or Superfund, products liability, breach of contract liability and premises liability litigation. Where appropriate, we may establish financial reserves for such proceedings. We also maintain insurance to mitigate certain of such risks. Costs for legal services are generally expensed as incurred.

Following receipt of information regarding potential improper payments being made by third party sales representatives of our Refining Solutions business, we promptly retained outside counsel and forensic accountants to investigate potential violations of the Company’s Code of Conduct, the Foreign Corrupt Practices Act (“FCPA”), and other potentially applicable laws. Based on this internal investigation, we have voluntarily self-reported potential issues relating to the use of third party sales representatives in our Refining Solutions business to the U.S. Department of Justice (“DOJ”) and Securities and Exchange Commission (“SEC”), and intend to cooperate with the DOJ and SEC in their review of these matters. In connection with our internal investigation, we have implemented, and are continuing to implement, appropriate remedial measures.

At this time, we are unable to predict the duration, scope, result or related costs associated with any investigations by the DOJ or SEC. We also are unable to predict what, if any, action may be taken by the DOJ or SEC or what penalties or remedial actions they may seek. Any determination that our operations or activities are not in compliance with existing laws or regulations, however, could result in the imposition of fines, penalties, disgorgement, equitable relief, or other losses. We do not believe, however, that any fines, penalties, disgorgement, equitable relief or other losses would have a material adverse effect on our financial condition or liquidity.

Indemnities

We are indemnified by third parties in connection with certain matters related to acquired and divested businesses. Although we believe that the financial condition of those parties who may have indemnification obligations to the Company is generally sound, in the event the Company seeks indemnity under any of these agreements or through other means, there can be no assurance that any party who may have obligations to indemnify us will adhere to their obligations and we may have to resort to legal action to enforce our rights under the indemnities.

The Company may be subject to indemnity claims relating to properties or businesses it divested, including properties or businesses of acquired businesses that were divested prior to the completion of the acquisition. In the opinion of management, and based upon information currently available, the ultimate resolution of any indemnification obligations owed to the Company or by the Company is not expected to have a material effect on the Company’s financial condition, results of operations or cash flows. See Note 16, “Other Noncurrent Liabilities,” for the tax indemnification liability related to the sale of the Chemetall Surface Treatment business.

Other

The Company has standby letters of credit and guarantees with various financial institutions. The following table summarizes our letters of credit and guarantee agreements (in thousands):



	2018		2019		2020		2021		2022		Thereafter
Letters of credit and other guarantees	$	40,347	$	5,830	$	1,672	$	975	$	1,074	$	13,581

The outstanding letters of credit are primarily related to insurance claim payment guarantees with expiration dates ranging from 2018 to 2022. The majority of the Company’s other guarantees have terms of one year and mainly consist of performance and environmental guarantees, as well as guarantees to customs and port authorities. The guarantees arose during the ordinary course of business.

We do not have recorded reserves for the letters of credit and guarantees as of December 31, 2017. We are unable to estimate the maximum amount of the potential future liability under guarantees and letters of credit. However, we accrue for any potential loss for which we believe a future payment is probable and a range of loss can be reasonably estimated. We believe our liability under such obligations is immaterial.

We currently, and are from time to time, subject to transactional audits in various taxing jurisdictions and to customs audits globally. We do not expect the financial impact of any of these audits to have a material adverse effect on the Company’s results of operations, financial condition or cash flows.