Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings (Accumulated Deficit) [Member]
BALANCE at Dec. 31, 2020	$ 555,907	$ 873	$ (246,088)	$ 658,423	$ 364	$ 142,335
BALANCE, shares at Dec. 31, 2020		87,265,000
BALANCE, shares at Dec. 31, 2020			(17,203,000)
Net income	30,753					30,753
Foreign currency translation	(129)				(129)
Unrealized loss on investments, net of tax	(221)				(221)
Share-based compensation expense	3,753			3,753
Common stock issued	(1,718)	$ 5	$ (2,032)	309
Common stock issued, shares		530,000	(160,000)
BALANCE at Mar. 31, 2021	588,345	$ 878	$ (248,120)	662,485	14	173,088
BALANCE, shares at Mar. 31, 2021		87,795,000
BALANCE, shares at Mar. 31, 2021			(17,363,000)
BALANCE at Dec. 31, 2021	$ 650,110	$ 887	$ (276,895)	674,242	(96)	251,972
BALANCE, shares at Dec. 31, 2021	88,724,438	88,724,000
BALANCE, shares at Dec. 31, 2021	(19,975,776)		(19,976,000)
Net income	$ 32,078					32,078
Foreign currency translation	(81)				(81)
Unrealized loss on investments, net of tax	(1,364)				(1,364)
Treasury stock purchased	(3,828)		$ (3,828)
Treasury stock purchased, shares			(363,000)
Share-based compensation expense	2,416			2,416
Common stock issued	(951)	$ 6	$ (1,610)	653
Common stock issued, shares		540,000	(146,000)
BALANCE at Mar. 31, 2022	$ 678,380	$ 893	$ (282,333)	$ 677,311	$ (1,541)	$ 284,050
BALANCE, shares at Mar. 31, 2022	89,264,034	89,264,000
BALANCE, shares at Mar. 31, 2022	(20,484,743)		(20,485,000)