Balance Sheet Components

Available-for-sale short-term investments (in thousands)



	As of
	September 27, 2015								December 31, 2014
	Cost		Unrealized Gain		Unrealized Loss		Estimated Fair Value		Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
U.S. treasuries	$	60,067	$	26	$	—	$	60,093	$	114,944	$	6	$	(15	)	$	114,935
Certificates of deposit	269		—		—		269		158		—		—			158
Total	$	60,336	$	26	$	—	$	60,362	$	115,102	$	6	$	(15	)	$	115,093

The Company’s short-term investments are primarily comprised of marketable securities that are classified as available-for-sale and consist of government securities with an original maturity or remaining maturity at the time of purchase of greater than three months and no more than 12 months. Accordingly, none of the available-for-sale securities have unrealized losses greater than 12 months.

Accounts receivable, net (in thousands)



	As of
	September 27, 2015			December 31, 2014
Gross accounts receivable	$	291,345		$	296,239
Allowance for doubtful accounts	(1,255		)	(1,255		)
Allowance for sales returns	(14,394		)	(17,489		)
Allowance for price protection	(1,523		)	(1,806		)
Total allowances	(17,172		)	(20,550		)
Total accounts receivable, net	$	274,173		$	275,689

Inventories (in thousands)



	As of
	September 27, 2015		December 31, 2014
Raw materials	$	2,382	$	3,625
Work in process	1		8
Finished goods	167,630		219,250
Total inventories	$	170,013	$	222,883

The Company records provisions for excess and obsolete inventory based on forecasts of future demand. While management believes the estimates and assumptions underlying its current forecasts are reasonable, there is risk that additional charges may be necessary if current forecasts are greater than actual demand.

Property and equipment, net (in thousands)



	As of
	September 27, 2015			December 31, 2014
Computer equipment	$	10,399		$	9,779
Furniture, fixtures and leasehold improvements	18,202			19,379
Software	30,140			29,294
Machinery and equipment	65,094			60,135
Total property and equipment, gross	123,835			118,587
Accumulated depreciation and amortization	(99,884		)	(88,893		)
Total property and equipment, net	$	23,951		$	29,694

Depreciation and amortization expense pertaining to property and equipment was $4.4 million and $13.8 million for the three and nine months ended September 27, 2015, respectively, and $4.6 million and $13.1 million for the three and nine months ended September 28, 2014, respectively.

Intangibles, net (in thousands)



	Gross		Accumulated Amortization			Net
September 27, 2015
Technology	$	61,099	$	(46,275	)	$	14,824
Customer contracts and relationships	56,500		(21,519		)	34,981
Other	10,545		(7,159		)	3,386
Total intangibles, net	$	128,144	$	(74,953	)	$	53,191



	Gross		Accumulated Amortization			Net
December 31, 2014
Technology	$	61,099	$	(39,341	)	$	21,758
Customer contracts and relationships	56,500		(16,205		)	40,295
Other	10,545		(6,368		)	4,177
Total intangibles, net	$	128,144	$	(61,914	)	$	66,230

Amortization of intangibles was $4.2 million and $13.0 million for the three and nine months ended September 27, 2015, respectively, and $4.5 million and $13.4 million for the three and nine months ended September 28, 2014, respectively.

Estimated amortization expense related to intangibles for each of the next five years and thereafter is as follows (in thousands):



Year Ending December 31	Amount
2015 (remaining three months)	$	4,244
2016	16,921
2017	11,386
2018	7,871
2019	6,028
Thereafter	6,741
Total estimated amortization expense	$	53,191

Other non-current assets (in thousands)



	As of
	September 27, 2015		December 31, 2014
Non-current deferred income taxes	$	38,805	$	38,696
Cost method investment	1,322		1,322
Other	7,278		8,059
Total other non-current assets	$	47,405	$	48,077

Other accrued liabilities (in thousands)



	As of
	September 27, 2015		December 31, 2014
Sales and marketing programs	$	52,130	$	54,582
Warranty obligation	47,928		44,888
Freight	6,550		6,827
Other	26,303		37,445
Total other accrued liabilities	$	132,911	$	143,742