Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 154,822	$ 155,440
Short-term investments	440,842	406,525
Accounts and notes receivable, net of allowance of $1,796 and $2,105 as of March 31, 2021 and December 31, 2020, respectively	185,373	229,201
Contract assets, net	72,472	63,945
Inventory	89,657	89,958
Prepaid expenses and other current assets	43,063	36,883
Total current assets	986,229	981,952
Property and equipment, net	112,119	105,494
Deferred tax assets, net	46,403	45,770
Intangible assets, net	8,642	9,448
Goodwill	25,194	25,205
Long-term investments	78,464	90,681
Long-term notes receivable, net	18,546	22,457
Long-term contract assets, net	26,341	20,099
Other assets	102,920	79,917
Total assets	1,404,858	1,381,023
Current liabilities:
Accounts payable	19,791	24,142
Accrued liabilities	41,097	59,843
Contract with customer, liability, current	165,086	163,959
Other current liabilities	5,667	5,431
Total current liabilities	239,775	256,331
Deferred revenue, net of current portion	116,107	111,222
Liability for unrecognized tax benefits	4,697	4,503
Long-term deferred compensation	4,825	4,732
Deferred tax liability, net	684	649
Other long-term liabilities	27,866	27,331
Total liabilities	393,954	404,768
Commitments and contingencies (Note 11)
Stockholders' equity:
Preferred stock, $0.00001 par value; 25,000,000 shares authorized; no shares issued and outstanding as of March 31, 2021 and December 31, 2020, respectively
Common stock, $0.00001 par value; 200,000,000 shares authorized; 64,673,091 and 63,766,555 shares issued and outstanding as of March 31, 2021 and December 31, 2020, respectively	1	1
Additional paid-in capital	1,044,724	962,159
Treasury stock at cost, 20,220,227 shares as of March 31, 2021 and December 31, 2020	(155,947)	(155,947)
Retained earnings	121,984	169,901
Accumulated other comprehensive income	142	141
Total stockholders' equity	1,010,904	976,255
Total liabilities and stockholders' equity	1,404,858	1,381,023
Current portion of deferred revenue
Current liabilities:
Contract with customer, liability, current	165,086	163,959
Customer deposits
Current liabilities:
Contract with customer, liability, current	$ 8,134	$ 2,956