Balance sheet components (Tables)

3 Months Ended

Mar. 31, 2019

Balance Sheet Related Disclosures [Abstract]

Accounts receivable, Net

Accounts receivable, net, consists of the following (in thousands):

	March 31, 2019			December 31, 2018
Accounts receivable	$	63,717		$	74,343
Trade notes receivable	1,757			672
Allowance for doubtful accounts	(264		)	(264		)
	$	65,210		$	74,751

Inventories, net

Inventories, net consist of the following (in thousands): 

	March 31, 2019		December 31, 2018
Raw materials	$	24,727	$	27,806
Work in process	15,240		13,044
Finished goods(1)	13,651		11,309
	$	53,618	$	52,159

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(1) Finished goods inventory at customer vendor managed inventory locations was $5.5 million and $5.6 million as of March 31, 2019 and December 31, 2018, respectively.

Prepaid expenses and other current assets

Prepaid expenses and other current assets consist of the following (in thousands):

	March 31, 2019		December 31, 2018
Prepaid taxes and taxes receivable	$	4,117	$	5,461
Transition services agreement receivable (see Note 6)	12,263		11,999
Deposits and other prepaid expenses	2,913		3,020
Other receivable	4,702		6,125
	$	23,995	$	26,605

Purchased intangible assets

Purchased intangible assets consist of the following (in thousands): 

	March 31, 2019							December 31, 2018
	Gross Assets		Accumulated Amortization			Net Assets		Gross Assets		Accumulated Amortization			Net Assets
Technology and patents	$	37,314	$	(35,457	)	$	1,857	$	37,029	$	(34,995	)	$	2,034
Customer relationships	15,269		(15,269		)	—		15,146		(15,026		)	120
Leasehold interest	1,269		(390		)	879		1,238		(374		)	864
	$	53,852	$	(51,116	)	$	2,736	$	53,413	$	(50,395	)	$	3,018

Amortization expense of purchased intangible assets

The following table presents details of the amortization expense of the Company’s purchased intangible assets as reported in the condensed consolidated statements of operations (in thousands):

	Three Months Ended March 31,
	2019		2018
Cost of goods sold	$	184	$	203
Operating expenses	119		119
Total	$	303	$	322

Estimated future amortization expense of purchased intangible assets

The estimated future amortization expense of purchased intangible assets as of March 31, 2019, is as follows (in thousands): 

2019 (remaining nine months)	$	552
2020	738
2021	645
2022	29
2023	29
Thereafter	743
	$	2,736

Accrued and other current liabilities

Accrued and other current liabilities consist of the following (in thousands): 

	March 31, 2019		December 31, 2018
Transition services agreement payables (see Note 6)	$	11,776	$	11,769
Employee-related	17,504		14,899
Asset sale related contingent liabilities (see Note 6)	6,918		6,751
Operating lease liabilities, current	2,274		—
Accrued warranty	739		672
Deferred revenue, current	481		1,114
Income and other taxes payable	1,055		1,580
Rusnano payment derivative	2,000		2,000
Accrued litigation settlement	1,150		2,645
Other accrued expenses	6,372		8,858
	$	50,269	$	50,288

Warranty accrual

The table below summarizes the movement in the warranty accrual, which is included in accrued and other current liabilities (in thousands):

	Three Months Ended March 31,
	2019			2018
Beginning balance	$	672		$	1,334
Warranty accruals	315			546
Settlements	(248		)	(181		)
Ending balance	$	739		$	1,699

Other noncurrent liabilities

Other noncurrent liabilities consist of the following (in thousands): 

	March 31, 2019		December 31, 2018
Pension and other employee-related	$	4,573	$	4,529
Deferred rent	—		3,058
Government grant	1,993		2,108
Capital lease obligation	—		282
Asset retirement obligations and other	3,556		3,522
	$	10,122	$	13,499