Fair Value Measurement

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value Measurements

9. Fair Value Measurement

The following tables summarize significant assets and liabilities measured at fair value in the consolidated balance sheets on a recurring basis for each of the fair value levels (in thousands):

	Fair Value Measurement at Reporting Date Using
December 31, 2018	Level 1		Level 2		Level 3		Total
Cash equivalents
Money market funds	$	84,613		—	$	—	$	84,613
Other noncurrent assets
Restricted cash		5,825		—		—		5,825
Total assets	$	90,438	$	—	$	—	$	90,438
Other current liabilities
Cash flow hedge	$	—	$	1,098	$	—	$	1,098
Total liabilities	$	—	$	1,098	$	—	$	1,098
December 31, 2017
Cash equivalents
Money market funds	$	37,284	$	—	$	—	$	37,284
Commercial paper		9,967		—		—		9,967
Other current assets
Cash flow hedge		—		1,400		—		1,400
Total assets	$	47,251	$	1,400	$	—	$	48,651

Interest Rate Swaps

In May 2018, we entered into the Third Amended and Restated Credit Agreement (as discussed further in Note 15), terminated the interest rate swap we entered into in January 2016 and entered into two new interest rate swaps designated as cash flow hedges with an effective date of May 2018. The two new cash flow hedges have a combined initial notional amount of $150.0 million and mature in May 2023. The interest rate swaps are designed to convert the interest rate on the term loan as discussed further in Note 15 from a variable interest rate of LIBOR plus an applicable margin to a fixed rate of 2.76% plus the same applicable margin.

Other Assets and Liabilities

The carrying values and estimated fair values of our financial instruments that are not required to be recorded at fair value in the consolidated balance sheets are as follows (in thousands): 

December 31,		2018				2017
	Fair Value Hierarchy	Carrying Value		Fair Value		Carrying Value		Fair Value
Assets:
Held-to-maturity marketable securities	Level 1	$	66,100	$	65,290	$	132,790	$	132,002
Liabilities (including current maturities):
2019 Notes1	Level 3	$	40,000	$	40,484	$	80,000	$	82,190
Credit Agreement - term loan1	Level 3		146,250		147,141		90,000		89,871
Credit Agreement - revolving credit facility1	Level 3		197,000		197,889		55,000		55,054

¹See Note 15 for definitions of, and more information about, the 2019 Notes and Credit Agreement.

At least annually, we measure certain nonfinancial assets and liabilities at fair value on a nonrecurring basis.  As of December 31, 2018 and 2017, the nonfinancial assets and liabilities included our asset retirement and reclamation obligations, as well as net assets held for sale and assets and corresponding liabilities associated with performance guarantees. See Note 1 for further discussion.

During the years ended December 31, 2018, 2017 and 2016, we had no material nonfinancial asset and liability fair value adjustments.