Balance Sheet Components

3 Months Ended

Mar. 31, 2020

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Investments

The fair value of the Company's available-for-sale investments as of March 31, 2020 and December 31, 2019 are as follows (in thousands):


	March 31, 2020
			Gross Unrealized						Estimated
	Amortized Cost		Gains		Losses		Fair Value
Money market funds	$	23,202	$	—	$	—	$	23,202
U.S. treasury bills	3,997		3		—		4,000
Commercial paper	9,938		—		—		9,938
Corporate bonds/notes	10,227		—		(30)		10,197
U.S. government securities	44,280		474		—		44,754
Asset-backed securities	5,183		—		(5)		5,178
	$	96,827	$	477	$	(35)	$	97,269
Classified as:
Cash equivalents										$	27,202
Short-term investments										70,067

							$	97,269


	December 31, 2019
			Gross Unrealized						Estimated
	Amortized Cost		Gains		Losses		Fair Value
Money market funds	$	34,363	$	—	$	—	$	34,363
Commercial paper	9,919		—		—		9,919
Corporate bonds/notes	10,180		—		(4)		10,176
U.S. government securities	44,450		9		(3)		44,456
Asset-backed securities	5,181		—		—		5,181
	$	104,093	$	9	$	(7)	$	104,095
Classified as:
Cash equivalents										$	34,363
Short-term investments										51,508
Long-term investments										18,224
							$	104,095

The following table summarizes the fair value of the Company’s cash equivalents, short-term and long-term investments classified by maturity as of March 31, 2020 and December 31, 2019 (in thousands):


	March 31,		December 31,
	2020		2019
Amounts maturing within one year	$	97,269	$	85,871
Amounts maturing after one year through two years	—		18,224
	$	97,269	$	104,095

Available-for-sale investments held as of March 31, 2020 had a weighted average days to maturity of 198 days.

The following table presents the Company's available-for-sale investments that were in an unrealized loss position as of March 31, 2020 and December 31, 2019 (in thousands):


	March 31, 2020						December 31, 2019
	Less than 12 months						Less than 12 months
Assets:	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Corporate bonds/notes	$	10,083	$	(30)	$	10,128	$	(4)
Asset-backed securities	5,174		(5)		—		—
U.S. government securities	—		—		19,067		(3)
	$	15,257	$	(35)	$	29,195	$	(7)

Inventories

Components of inventories were as follows:


(in thousands)	March 31,		December 31,
	2020		2019
Raw materials	$	1,539	$	1,203

Finished products	10,562		9,119
Total	$	12,101	$	10,322

As of March 31, 2020 and December 31, 2019, there were no work-in-process inventories.

Accrued Liabilities

Accrued liabilities consist of the following:


(in thousands)	March 31,		December 31,
	2020		2019
Accrued payroll and related expenses	$	5,642	$	9,151
Provision for sales returns	2,735		2,419
Accrued professional services	380		682
Operating lease liability	788		769
Accrued royalty expense	477		470
Deferred revenue	174		304
Accrued travel expenses	276		431
Accrued clinical expenses	181		241
Accrued other expenses	472		567
Total	$	11,125	$	15,034