Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2017

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.

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

The following schedule details the future non-cancelable minimum lease payments for the next five years and thereafter (in thousands):

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