Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 172,250	$ 349,462
Short-term investments	178,534	0
Accounts and notes receivable, net of allowance of $1,567 and $1,882 as of December 31, 2019 and 2018, respectively	146,878	130,579
Contract assets, net	47,718	13,960
Inventory	38,845	33,763
Prepaid expenses and other current assets	34,866	30,391
Total current assets	619,091	558,155
Property and equipment, net	43,770	37,893
Deferred tax assets, net	27,688	19,347
Intangible assets, net	12,771	15,935
Goodwill	25,013	24,981
Long-term investments	45,499	0
Long-term notes receivable, net of current portion	31,598	40,230
Other assets	40,209	22,999
Total assets	845,639	719,540
Current liabilities:
Accounts payable	25,874	15,164
Accrued liabilities	45,001	41,092
Contract with customer, liability, current	117,864	107,016
Other current liabilities	3,853	37
Total current liabilities	195,566	166,011
Deferred revenue, net of current portion	87,936	74,417
Liability for unrecognized tax benefits	3,832	2,849
Long-term deferred compensation	3,936	3,235
Deferred tax liability, net	354	0
Other long-term liabilities	10,520	5,704
Total liabilities	302,144	252,216
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock, $0.00001 par value; 25,000,000 shares authorized; no shares issued and outstanding as of December 31, 2019 and 2018	0	0
Common stock, $0.00001 par value; 200,000,000 shares authorized; 59,497,759 and 58,810,637 shares issued and outstanding as of December 31, 2019 and 2018, respectively	1	1
Additional paid-in capital	528,272	453,400
Treasury stock at cost, 20,220,227 shares as of December 31, 2019 and 2018	(155,947)	(155,947)
Retained earnings	172,265	171,383
Accumulated other comprehensive loss	(1,096)	(1,513)
Total stockholders’ equity	543,495	467,324
Total liabilities and stockholders' equity	845,639	719,540
Current portion of deferred revenue
Current liabilities:
Contract with customer, liability, current	117,864	107,016
Customer deposits
Current liabilities:
Contract with customer, liability, current	$ 2,974	$ 2,702