Balance Sheet Components (in thousands)

Available-for-sale short-term investments



	As of
	December 31, 2015									December 31, 2014
	Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value		Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
U.S. treasuries	$	95,057	$	1	$	(65	)	$	94,993	$	114,944	$	6	$	(15	)	$	114,935
Certificates of deposits	147		—		—			147		158		—		—			158
Total	$	95,204	$	1	$	(65	)	$	95,140	$	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 twelve months. Accordingly, none of the available-for-sale securities have unrealized losses greater than 12 months.

Cost method investments

The carrying value of the Company's cost method investments was $0.1 million and $1.3 million for the years ended December 31, 2015 and December 31, 2014. These investments are included in other non-current assets in the consolidated balance sheets and are carried at cost, adjusted for any impairment, because the Company does not have a controlling interest and does not have the ability to exercise significant influence over these companies. The Company monitors these investments for impairment on a quarterly basis, and adjusts carrying value for any impairment charges recognized. There were no impairments recognized in the years ended December 31, 2015, December 31, 2014 and December 31, 2013. Realized gains and losses on these investments are reported in other income (expense), net in the consolidated statements of operations. No material gains or losses were recorded in the years ended December 31, 2015, 2014 and 2013.

Accounts receivable, net



	As of
	December 31, 2015			December 31, 2014
Gross accounts receivable	$	309,926		$	296,239
Allowance for doubtful accounts	(1,255		)	(1,255		)
Allowance for sales returns	(15,904		)	(17,489		)
Allowance for price protection	(2,125		)	(1,806		)
Total allowances	(19,284		)	(20,550		)
Total accounts receivable, net	$	290,642		$	275,689

Inventories



	As of
	December 31, 2015		December 31, 2014
Raw materials	$	4,292	$	3,625
Work-in-process	2		8
Finished goods	208,824		219,250
Total inventories	$	213,118	$	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



	As of
	December 31, 2015			December 31, 2014
Computer equipment	$	11,161		$	9,779
Furniture, fixtures and leasehold improvements	18,317			19,379
Software	30,396			29,294
Machinery and equipment	66,662			60,135
Total property and equipment, gross	126,536			118,587
Accumulated depreciation and amortization	(104,152		)	(88,893		)
Total property and equipment, net	$	22,384		$	29,694

Depreciation and amortization expense pertaining to property and equipment was $18.1 million, $17.6 million and $17.3 million for the years ended December 31, 2015, 2014 and 2013, respectively.

Intangibles, net

The following tables present details of the Company’s purchased intangibles:



	Gross		Accumulated Amortization			Net
December 31, 2015
Technology	$	61,099	$	(48,485	)	$	12,614
Customer contracts and relationships	56,500		(23,290		)	33,210
Other	10,545		(7,422		)	3,123
Total intangibles, net	128,144		(79,197		)	48,947



	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 purchased intangibles in the years ended December 31, 2015, 2014 and 2013 was $17.3 million, $17.9 million and $15.5 million, respectively. In the year ended December 31, 2013, the Company recorded an impairment charge of $2.0 million due to the abandonment of IPR&D acquired as part of the AirCard acquisition. No impairment charges were recorded in the years ended December 31, 2015 and 2014.

Estimated amortization expense related to finite-lived intangibles for each of the next five years and thereafter is as follows:



Year Ended December 31,	Amount
2016	$	16,921
2017	11,386
2018	7,871
2019	6,028
2020	5,316
Thereafter	1,425
Total expected amortization expense	$	48,947

Goodwill

The changes in the carrying amount of goodwill during the years ended December 31, 2015 and 2014 are as follows:



	Retail		Commercial		Service Provider			Total
Goodwill at December 31, 2013	$	45,442	$	36,279	$	74,196		$	155,916
Goodwill impairment charges	—		—		(74,196		)	(74,196		)
Goodwill at December 31, 2014	45,442		$	36,279	—			81,721
Goodwill impairment charges	—		—		—			—
Goodwill at December 31, 2015	$	45,442	$	36,279	$	—		$	81,721

In the fourth fiscal quarter of 2015, the Company completed the annual impairment test of goodwill. The test was performed as of the first day of the fourth quarter.

The Company performed a qualitative test for goodwill impairment of the retail and commercial reporting units as of September 28, 2015. Based upon the results of the qualitative testing, the respective fair values of the retail and commercial reporting units were substantially in excess of these reporting units’ carrying values. The Company believes it is more-likely-than-not that the fair value of these reporting units are greater than their respective carrying values and therefore performing the first step of the two-step impairment test for the retail and commercial reporting units was unnecessary. No goodwill impairment was recognized for the retail and commercial reporting units in the years ended December 31, 2015, 2014 or 2013.

In the fourth quarter of fiscal year 2014, the Company recorded a goodwill impairment charge of $74.2 million related to the service provider reporting unit in the year ended December 31, 2014.

There were no impairments to goodwill in the years ended December 31, 2015 and 2013. Accumulated goodwill impairment charges for the years ended December 31, 2015 and 2014, was $74.2 million and $74.2 million, respectively.

Other non-current assets



	As of
	December 31, 2015			December 31, 2014
Non-current deferred income taxes	$	68,445	*	$	38,696
Cost method investments	105			1,322
Other	7,824			8,059
Total other non-current assets	$	76,374		$	48,077

* Includes a reclassification of the net current deferred tax asset to the net non-current deferred tax asset in the consolidated Balance Sheet as of December 31, 2015. No prior periods were retrospectively adjusted. Refer to Note 1, The Company and Summary of Significant Accounting Policies, for additional information regarding the early adoption of the ASU 2015-17.

Other accrued liabilities



	As of
	December 31, 2015		December 31, 2014
Sales and marketing programs	$	69,693	$	54,582
Warranty obligation	56,706		44,888
Freight	5,748		6,827
Other	34,135		37,445
Total other accrued liabilities	$	166,282	$	143,742