The Company has investments in debt securities which include corporate bonds and notes, treasury and agency notes and bills, commercial paper, certificates of deposit, and in equity securities consisting of money market funds and common equity securities of a publicly traded Japanese company. The Company classifies its debt securities as available-for-sale (“AFS”), which are accounted for at fair value with credit related losses recognized as a provision for credit loss expense in its Condensed Consolidated Statements of Operations and all non-credit related unrealized gains and losses recognized in accumulated other comprehensive income or loss on the Condensed Consolidated Balance Sheets. Under ASU 2016-01 (Topic 321), equity securities are measured at fair value with unrealized gains and losses recognized in other income and expense, net, on the Condensed Consolidated Statements of Operations.

The following is a summary of marketable securities at March 31, 2020 and December 31, 2019 (in thousands):

	March 31, 2020
	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Allowance for Credit Losses		Estimated Fair Values
Marketable securities
Corporate bonds and notes	$	32,608	$	16	$	(272	)	$	—	$	32,352
Commercial paper		1,324		1		—			—		1,325
Total debt securities		33,932		17		(272	)		—		33,677
Money market funds		34,791		—		—			—		34,791
Marketable equity securities		3,405		—		(3,015	)		—		390
Total equity securities		38,196		—		(3,015	)		—		35,181
Total marketable securities	$	72,128	$	17	$	(3,287	)	$	—	$	68,858
Reported in:
Cash and cash equivalents										$	34,791
Available-for-sale debt securities											33,677
Equity securities											390
Total marketable securities										$	68,858

	December 31, 2019
	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Values
Marketable securities
Corporate bonds and notes	$	41,730	$	29	$	(13	)	$	41,746
Commercial paper		4,052		4		—			4,056
Total debt securities		45,782		33		(13	)		45,802
Money market funds		2,601		—		—			2,601
Marketable equity securities		3,405		—		(2,281	)		1,124
Total equity securities		6,006		—		(2,281	)		3,725
Total marketable securities	$	51,788	$	33	$	(2,294	)	$	49,527
Reported in:
Cash and cash equivalents								$	2,601
Available-for-sale debt securities									45,802
Equity securities									1,124
Total marketable securities								$	49,527

At March 31, 2020 and December 31, 2019, the Company had $142.5 million and $121.5 million, respectively, in cash, cash equivalents and short-term investments. These balances include $73.6 million and $72.0 million in cash held in operating accounts not included in the tables above at March 31, 2020 and December 31, 2019, respectively.

The gross realized gains and losses on sales of marketable debt securities were not significant during the three months ended March 31, 2020 and 2019, respectively.

Unrealized losses on marketable debt securities were $0.3 million and $0.1 million, net of tax, as of March 31, 2020 and December 31, 2019, respectively. The Company evaluated whether the decline in fair value has resulted from credit losses or other factors and concluded these amounts were related to temporary fluctuations in value of AFS securities and were due primarily to changes in interest rates and market conditions of the underlying securities. In addition, the contractual terms of those investments do not permit the issuer to settle the securities at a price less than the amortized cost bases of the investments. The Company does not intend to sell the investments and it is more likely than not that it will not be required to sell the investments before recovery of their amortized cost bases. For the three months ended March 31, 2020, the Company did not recognize a provision for credit loss expense related to its AFS debt securities. For the three months ended March 31, 2019, the Company did not record any impairment charges related to its AFS debt securities.

The following table summarizes the fair value and gross unrealized losses related to individual AFS debt securities at March 31, 2020 and December 31, 2019, which have been in a continuous unrealized loss position, aggregated by investment category and length of time (in thousands):

	Less Than 12 Months					12 Months or More					Total
March 31, 2020	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Corporate bonds and notes	$	21,256	$	(265	)	$	3,995	$	(7	)	$	25,251	$	(272	)
Total	$	21,256	$	(265	)	$	3,995	$	(7	)	$	25,251	$	(272	)

	Less Than 12 Months					12 Months or More					Total
December 31, 2019	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Corporate bonds and notes	$	20,031	$	(10	)	$	8,753	$	(3	)	$	28,784	$	(13	)
Total	$	20,031	$	(10	)	$	8,753	$	(3	)	$	28,784	$	(13	)

The estimated fair value of marketable debt securities by contractual maturity at March 31, 2020 is shown below (in thousands). Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations without call or prepayment penalties.

On September 19, 2018, the Company purchased seven million common shares of Onkyo Corporation (“Onkyo”), a publicly traded Japanese company and a long-standing customer of the Company, pursuant to the Capital Alliance Agreement (“Agreement”) entered into between the two parties on September 3, 2018. Upon making the investment, the Company held a 6.3% ownership interest in Onkyo. Due to changes in business expectations, the Company determined not to continue discussions on the business alliance. On July 5, 2019, the Company sold approximately 2.8 million shares of Onkyo stock and realized a gain of $0.9 million. There were no sales of the Onkyo investment during the three months ended March 31, 2020 and 2019. The Company intends to sell the remaining shares over time depending on market conditions.

The Company recorded unrealized losses on its Onkyo investment of $0.7 million and $0.4 million during the three months ended March 31, 2020 and 2019, respectively. Cumulative unrealized losses on the investment amounted to $3.0 million through March 31, 2020.

From time to time, the Company may use derivative financial instruments to manage foreign currency exchange rate risk. The Company does not enter into derivative transactions for trading purposes. Cash flows from the derivative programs are classified as cash flows from operating activities in the Condensed Consolidated Statements of Cash Flows.

The Company’s derivative financial instruments consist of deliverable and non-deliverable foreign currency forward contracts, which are used primarily to hedge balance sheet and certain expenditure exposures. These instruments are generally short-term in nature, with typical maturities of less than one year, and are subject to fluctuations in foreign exchange rates. Fair values for derivative financial instruments are based on prices computed using third-party valuation models and are classified as Level 2 in accordance with the three-level hierarchy of fair value measurements. All significant inputs to the third-party valuation models are observable in active markets. Inputs include current market-based parameters such as forward rates, yield curves and credit default swap pricing. For additional information related to the three-level hierarchy of fair value measurements, see “Note 6 – Fair Value.”

Under the Company’s policy election, these derivatives are not designated as hedge instruments, which are measured and reported at fair value. Changes in the fair value of these undesignated derivatives are reported in other income and expense, net, on the Condensed Consolidated Statements of Operations. Realized losses and changes in the estimated fair value of the derivatives were not significant in the three months ended March 31, 2020 and 2019.

The notional and fair values of all derivative instruments were as follows (in thousands):