CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows provided by (used in) operating activities:
Net loss	$ (4,828)	$ (11,016)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	1,178	428
Stock-based compensation	729	2,103
Foreign currency translation loss	361	0
Other	0	117
Changes in operating assets and liabilities:
Accounts and other receivables	(2,202)	(454)
Prepaid expenses and other current assets	4,820	1,028
Other assets	(22)	(11,642)
Accounts payable	122	8,763
Accrued compensation	(855)	(2,588)
Other current liabilities	422	2,092
Deferred revenue	(1,302)	(904)
Other long-term liabilities	261	4,495
Net cash used in operating activities	(1,316)	(7,578)
Cash flows provided by (used in) investing activities:
Purchases of short-term investments	0	(8,930)
Proceeds from maturities of short-term investments	3,000	8,000
Purchases of property and equipment	(21)	(6)
Net cash provided by (used in) investing activities	2,979	(936)
Cash flows provided by (used in) financing activities:
Cash paid for purchases of treasury shares	(11,975)	0
Proceeds from issuance of common stock under employee stock purchase plan	63	109
Proceeds from stock options exercises	0	71
Net cash provided by (used in) financing activities	(11,912)	180
Net decrease in cash and cash equivalents	(10,249)	(8,334)
Cash and cash equivalents:
Beginning of period	86,478	110,988
End of period	76,229	102,654
Supplemental disclosure of cash flow information:
Leased assets obtained in exchange for new operating lease liabilities	577	0
Cash paid for income taxes	19	23
Supplemental disclosure of non-cash operating, investing, and financing activities:
Release of restricted stock units and awards under company stock plan	$ 1,356	$ 6,680