	As of
	December 31, 2020		December 31, 2019
	(In thousands)
Raw materials	$	7,756	$	28,871
Finished goods		164,356		206,618
Total	$	172,112	$	235,489

The Company records provisions for excess and obsolete inventory based on assumptions about future demand and market conditions and the amounts incurred were $7.9 million, $3.9 million and $2.9 million for the years ended December 31, 2020, 2019 and 2018, respectively. 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.

	As of
	December 31, 2020			December 31, 2019
	(In thousands)
Computer equipment	$	10,550		$	9,883
Furniture, fixtures and leasehold improvements		18,674			18,623
Software		29,499			27,865
Machinery and equipment		72,156			59,637
Total property and equipment, gross		130,879			116,008
Accumulated depreciation and amortization		(114,799	)		(98,325	)
Total	$	16,080		$	17,683

Depreciation and amortization expense pertaining to property and equipment was $12.7 million, $12.3 million and $10.5 million for the years ended December 31, 2020, 2019 and 2018, respectively.

	As of December 31, 2020							As of December 31, 2019
	Gross		Accumulated Amortization			Net		Gross		Accumulated Amortization			Net
	(In thousands)
Technology	$	59,799	$	(57,835	)	$	1,964	$	59,799	$	(57,406	)	$	2,393
Customer contracts and relationships		56,800		(55,534	)		1,266		56,800		(50,297	)		6,503
Other		10,345		(9,676	)		669		10,345		(9,137	)		1,208
Total	$	126,944	$	(123,045	)	$	3,899	$	126,944	$	(116,840	)	$	10,104

Amortization of purchased intangibles in the years ended December 31, 2020, 2019 and 2018 was $6.2 million, $7.0 million and $8.3 million, respectively. No impairment charges were recorded in the years ended December 31, 2020, 2019 and 2018.

As of December 31, 2020, estimated amortization expense related to finite-lived intangibles for each of the next five years and thereafter is as follows (in thousands):

	As of
	December 31, 2020		December 31, 2019
	(In thousands)
Non-current deferred income taxes	$	68,323	$	58,930
Long-term investments		8,395		8,147
Other		6,032		7,202
Total	$	82,750	$	74,279

The Company’s long-term investments are primarily comprised of equity investments without readily determinable fair values. The changes in the carrying value of these investments during the years ended December 31, 2020 and 2019 are as follows (in thousands):

Carrying value as of December 31, 2018	$	2,886
Additions		5,484
Downward adjustments for observable price changes		(223	)
Carrying value as of December 31, 2019		8,147
Additions		5,850
Impairment and downward adjustments for observable price changes		(6,239	)
Carrying value as of December 31, 2020	$	7,758

⁽¹⁾The balance as of December 31, 2020 did not include the investment in limited partnership fund of $0.6 million.

For the equity investments without readily determinable fair values as of December 31, 2020, cumulative downward adjustments for price changes and impairment was $7.9 million and cumulative upward adjustments for price changes was $0.2 million.

	As of
	December 31, 2020		December 31, 2019
	(In thousands)
Current operating lease liabilities	$	9,149	$	9,357
Sales and marketing		83,561		85,605
Warranty obligations		9,240		10,556
Sales returns⁽¹⁾		66,972		52,612
Freight and duty		14,885		5,633
Other		34,568		25,784
Total	$	218,375	$	189,547