Condensed consolidated financial statement details

Inventory

Inventory consisted of the following:



(in thousands)	September 30, 2015		December 31, 2014
Components	$	14,478	$	4,324
Finished goods	275,043		148,702
Total inventory	$	289,521	$	153,026

Property and equipment, net

Property and equipment, net consisted of the following:



(in thousands)	Useful life (in years)	September 30, 2015			December 31, 2014
Leasehold improvements	3–7	$	24,050		$	22,787
Computers, software, equipment and furniture	2–4	42,936			24,636
Tooling	1–2	19,876			16,159
Construction in progress		19,507			3,944
Tradeshow equipment and other	2-5	4,016			3,830
Total		110,385			71,356
Less: Accumulated depreciation and amortization		(42,741		)	(29,800)
Property and equipment, net		$	67,644		$	41,556

Construction in progress includes costs primarily related to construction of leasehold improvements to the Company's office facilities. No interest was capitalized during the three and nine months ended September 30, 2015 and 2014.

Acquisitions and acquired intangible assets and goodwill

During the nine months ended September 30, 2015, the Company completed several acquisitions qualifying as business combinations for aggregate consideration of $70.2 million, most of which was cash consideration. These acquisitions were not material to the Company's condensed consolidated financial statements, either individually or in the aggregate, and therefore actual and proforma disclosures under the applicable accounting guidance have not been presented.

The following table summarizes the preliminary allocation of the fair values of the assets acquired and liabilities assumed, and the related useful lives, where applicable:



(in thousands)	Estimated useful life (in years)	Fair value
Purchased technology	4 - 6 years	$	25,676
In-process research and development (IPR&D)		6,600
Net liabilities assumed		(353		)
Deferred income tax liabilities		(4,676		)
Net assets acquired		27,247
Goodwill		43,000
Total fair value consideration		$	70,247

Goodwill represents the excess of the purchase price over the fair value of the net assets acquired and is primarily attributable to expected synergies in the technologies that can be leveraged by the Company in future product offerings. Goodwill is not expected to be deductible for tax purposes.

The following table summarizes the Company's acquired intangible assets:




	September 30, 2015							December 31, 2014
(in thousands)	Gross carrying amount		Accumulated amortization			Net carrying value		Net carrying value
Purchased technology and other amortizable assets	$	32,951	$	(7,019	)	$	25,932	$	2,922
IPR&D and other non-amortizable assets	6,615		—			6,615		15
Total intangible assets	$	39,566	$	(7,019	)	$	32,547	$	2,937

As of September 30, 2015, technological feasibility has not been established for IPR&D assets; they have no alternative future use and, as such, continue to be accounted for as indefinite-lived intangible assets.

Amortization expense for the nine months ended September 30, 2015 and 2014 was $2.7 million and $0.8 million, respectively. Estimated amortization expense for future periods as of September 30, 2015, is as follows:



(in thousands)	Total
Year ending December 31,
Remainder of 2015	$	1,521
2016	5,956
2017	5,172
2018	4,779
2019	4,269
Thereafter	4,235
	$	25,932

The carrying amount of goodwill was $57.1 million and $14.1 million as of September 30, 2015 and December 31, 2014, respectively. The increase during the nine months ended September 30, 2015 was entirely attributable to goodwill acquired. The Company did not have any goodwill impairments during the periods presented.