CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows provided by (used in) operating activities:
Net income (loss)	$ 11,148	$ (2,685)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	575	1,681
Stock-based compensation	1,997	3,433
Foreign currency remeasurement losses	612	66
Unrealized gain on available-for-sale debt securities	(490)	0
Other	68	(161)
Changes in operating assets and liabilities:
Accounts and other receivables	(1,953)	2,019
Prepaid expenses and other current assets	870	4,147
Long-term deposits	33	(4,889)
Other assets	2,097	1,471
Accounts payable	(30)	(642)
Accrued compensation	(272)	(2,013)
Other current liabilities	917	(1,465)
Deferred revenue	(3,734)	(2,984)
Other long-term liabilities	(1,116)	(966)
Net cash provided by (used in) operating activities	10,722	(2,988)
Cash flows provided by (used in) investing activities:
Purchases of marketable securities	(34,443)	0
Proceeds from sale of derivative instruments	1,757	0
Proceeds from maturities of short-term investments	0	3,000
Purchases of property and equipment	(89)	(40)
Net cash provided by (used in) investing activities	(32,775)	2,960
Cash flows provided by (used in) financing activities:
Proceeds from issuance of common stock, net	50,118	0
Cash paid for purchases of treasury shares	0	(30,642)
Proceeds from issuance of common stock under employee stock purchase plan	150	134
Proceeds from stock options exercises	2,864	19
Net cash provided by (used in) financing activities	53,132	(30,489)
Net increase (decrease) in cash and cash equivalents	31,079	(30,517)
Cash and cash equivalents:
Beginning of period	59,522	86,478
End of period	90,601	55,961
Supplemental disclosure of cash flow information:
Cash paid for income taxes	88	65
Supplemental disclosure of non-cash operating, investing, and financing activities:
Release of restricted stock units and awards under stock plan	4,081	2,801
Leased assets obtained in exchange for new operating lease liabilities	$ 0	$ 577