FAIR VALUE MEASUREMENTS

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS

We account for certain assets and liabilities at fair value. The hierarchy below lists three levels of fair value based on the extent to which inputs used in measuring fair value are observable in the market. We categorize each of our fair value measurements in one of these three levels based on the lowest level input that is significant to the fair value measurement in its entirety. These levels are:

• Level 1: Quoted prices in active markets for identical assets or liabilities;

• Level 2: Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and

• Level 3: Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Assets and liabilities measured at fair value on a recurring basis are summarized as follows (in thousands): 

	Level 1		Level 2		Level 3		Total
December 31, 2019:
Asset retirement obligations (1)	$	—	$	—	$	2,322	$	2,322
December 31, 2018:
Available-for-sale securities	—		2,309		—		2,309
Asset retirement obligations (1)	$	—	$	—	$	2,090	$	2,090

⁽¹⁾  We calculated the fair value of asset retirement obligations ("ARO") by discounting the estimated amount using the Treasury bill rate adjusted for our credit risk. At December 31, 2019 and 2018, the balance is included in "Other long-term liabilities," in the accompanying consolidated balance sheets.

The following table provides a summary of changes in our Level 3 asset retirement obligations (in thousands): 

	2019		2018		2017
Balance, January 1	$	2,090	$	1,936	$	2,810
Accretion	232		154		197
Subsequent revision of estimated obligation	—		—		449
Payments	—		—		(1,520		)
Balance, December 31	$	2,322	$	2,090	$	1,936

As of December 31, 2019, the Company had no available-for-sale debt securities. In 2018, the Company held $2.3 million of available-for-sale debt securities which are reported at fair value on the Company's consolidated balance sheets in "Deposits and other assets." If a decline in the fair value of a marketable security below the Company's cost basis is determined to be other than temporary, such marketable security is written down to its estimated fair value as a new cost basis and the amount of the write-down is included in earnings as an impairment charge. The Company may sell certain of its marketable securities prior to their stated maturities for strategic reasons including, but not limited to, anticipation of credit deterioration and maturity management.

The fair values of our Level 2 available-for-sale debt securities, based upon quoted prices for similar items in active markets, are as follows (in thousands):

	December 31, 2019
	Cost		Unrealized Gain		Unrealized Loss			Converted to Cash			Fair Value
Japanese Corporate Bonds	$	2,221	$	198	$	(156	)	$	(2,263	)	$	—
Japanese Government Bonds	88		7		(6		)	(89		)	—
Total Bonds	$	2,309	$	205	$	(162	)	$	(2,352	)	$	—
	December 31, 2018
	Cost		Unrealized Gain		Unrealized Loss			Converted to Cash			Fair Value
Japanese Corporate Bonds	$	2,184	$	144	$	(107	)	$	—		$	2,221
Japanese Government Bonds	87		5		(4		)	—			88
Total Bonds	$	2,271	$	149	$	(111	)	$	—		$	2,309

The fair values of our other Level 2 debt liabilities, based upon quoted prices for our term loans, are as follows (in thousands): 

	December 31,
	2019				2018
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Term loan	$	425,856	$	262,966	$	429,143	$	428,071
Revolving credit facility	20,000		12,350		—		—