CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Cash flows from operating activities:
Net income (loss)	$ (4,647)	$ (4,128)	$ (58,351)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	2,610	2,370	10,251
Accrued Interest	(221)	0	(94)
Asset write-downs and impairment of field equipment	135	176	649
Share-based compensation	25,045	18,863	94,900
Foreign currency remeasurement loss (gain)	249	2,157	3,231
Decrease (increase) in accounts receivables	(7,461)	4,624	5,270
Amortization of discount (premium)	684	603	3,101
Decrease (increase) in inventories	(4,804)	(1,296)	2,483
Decrease (increase) in other long-term assets	1,863	1,432	4,519
Increase (decrease) in accounts payables and accrued expenses	(14,809)	(2,626)	27,777
Increase (decrease) in other long-term liabilities	(2,331)	(4,394)	(10,980)
Net cash provided by (used in) operating activities	(3,687)	17,780	82,756
Cash flows from investing activities:
Purchase of property, equipment and field equipment	(5,093)	(3,981)	(24,170)
Proceeds from maturity of short-term investments	279,000	608,000	958,000
Purchase of short-term investments	(291,317)	(549,848)	(1,078,664)
Net cash provided by (used in) investing activities	(17,410)	54,171	(144,834)
Cash flows from financing activities:
Proceeds from issuance of shares, net	0	0	4,546
Repayment of long-term debt	(7)	(6)	(26)
Exercise of options	3,148	7,961	21,182
Net cash provided by (used in) financing activities	3,141	7,955	25,702
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(25)	(102)	(188)
Increase (decrease) in cash, cash equivalents and restricted cash	(17,981)	79,804	(36,564)
Cash, cash equivalents and restricted cash at the beginning of the period	209,609	246,173	246,173
Cash, cash equivalents and restricted cash at the end of the period	191,628	325,977	209,609
Cash paid during the period for:
Income taxes paid (refunded), net	1,173	(2,405)	3,110
Interest paid	1	1	101
Non-cash activities:
Right-of-use assets obtained in exchange for lease liabilities	$ 3,580	$ 284	$ 5,387