Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 485,928	$ 127,210
Accounts receivable and unbilled receivables, net of allowances of $4,286 and $3,227, respectively	190,117	218,362
Inventories	96,298	108,011
Prepaid expenses	16,027	14,478
Other current assets	41,044	15,177
Total current assets	829,414	483,238
Property and equipment, net	59,073	54,246
Long-term investment in sales-type leases, net	22,156	19,750
Operating lease right-of-use assets	55,114	56,130
Goodwill	499,309	336,539
Intangible assets, net	168,211	124,867
Long-term deferred tax assets	15,019	14,142
Prepaid commissions	56,919	48,862
Other long-term assets	119,289	103,036
Total assets	1,824,504	1,240,810
Current liabilities:
Accounts payable	40,309	46,380
Accrued compensation	55,750	44,155
Accrued liabilities	80,311	55,567
Deferred revenues, net	100,053	90,894
Total current liabilities	276,423	236,996
Long-term deferred revenues	5,673	7,083
Long-term deferred tax liabilities	39,633	39,090
Long-term operating lease liabilities	48,897	50,669
Other long-term liabilities	19,174	11,718
Revolving credit facility	0	50,000
Convertible senior notes, net	467,201	0
Total liabilities	857,001	395,556
Commitments and contingencies (Note 13)
Stockholders’ equity:
Preferred stock, $0.001 par value, 5,000 shares authorized; no shares issued	0	0
Common stock, $0.001 par value, 100,000 shares authorized; 52,677 and 51,277 shares issued; 42,783 and 42,132 shares outstanding, respectively	53	51
Treasury stock at cost, 9,894 and 9,145 shares outstanding, respectively	(238,109)	(185,074)
Additional paid-in capital	920,359	780,931
Retained earnings	290,722	258,792
Accumulated other comprehensive loss	(5,522)	(9,446)
Total stockholders’ equity	967,503	845,254
Total liabilities and stockholders’ equity	$ 1,824,504	$ 1,240,810