Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance at Dec. 31, 2020	$ 76,069	$ 22	$ 390,803	$ 5	$ (314,761)
Balance (in shares) at Dec. 31, 2020		22,097,820
Stock-based compensation expense	1,026		1,026
Stock-based compensation expense		10,149
Issuance of common stock from stock grants and option exercises	182		182
Issuance of common stock from stock grants and option exercises, shares		38,058
Issuance of common stock for public offering, net of issuance costs	49,250	$ 9	49,241
Issuance of common stock for public offering, net of issuance costs, shares		9,185,000
Net income (loss)	(22,438)				(22,438)
Balance at Mar. 31, 2021	104,089	$ 31	441,252	5	(337,199)
Balance (in shares) at Mar. 31, 2021		31,331,027
Balance at Dec. 31, 2020	76,069	$ 22	390,803	5	(314,761)
Balance (in shares) at Dec. 31, 2020		22,097,820
Unrealized loss on available-for-sale debt securities	(4)
Net income (loss)	(67,604)
Balance at Sep. 30, 2021	60,736	$ 31	443,069	1	(382,365)
Balance (in shares) at Sep. 30, 2021		31,392,618
Balance at Mar. 31, 2021	104,089	$ 31	441,252	5	(337,199)
Balance (in shares) at Mar. 31, 2021		31,331,027
Stock-based compensation expense	983		983
Stock-based compensation expense		13,713
Issuance of common stock from stock grants and option exercises	23		23
Issuance of common stock from stock grants and option exercises, shares		5,000
Unrealized loss on available-for-sale debt securities	(3)			(3)
Net income (loss)	(19,928)				(19,928)
Balance at Jun. 30, 2021	85,164	$ 31	442,258	2	(357,127)
Balance (in shares) at Jun. 30, 2021		31,349,740
Stock-based compensation expense	713		713
Stock-based compensation expense		15,961
Issuance of common stock from stock grants and option exercises	98		98
Issuance of common stock from stock grants and option exercises, shares		26,917
Unrealized loss on available-for-sale debt securities	(1)			(1)
Net income (loss)	(25,238)				(25,238)
Balance at Sep. 30, 2021	60,736	$ 31	443,069	$ 1	(382,365)
Balance (in shares) at Sep. 30, 2021		31,392,618
Balance at Dec. 31, 2021	41,089	$ 31	443,752		(402,694)
Balance (in shares) at Dec. 31, 2021		31,409,707
Stock-based compensation expense	515		515
Stock-based compensation expense		32,684
Issuance of common stock from stock grants and option exercises	16		16
Issuance of common stock from stock grants and option exercises, shares		34,662
Net income (loss)	(14,536)				(14,536)
Balance at Mar. 31, 2022	27,084	$ 31	444,283		(417,230)
Balance (in shares) at Mar. 31, 2022		31,477,053
Balance at Dec. 31, 2021	41,089	$ 31	443,752		(402,694)
Balance (in shares) at Dec. 31, 2021		31,409,707
Net income (loss)	32,212
Balance at Sep. 30, 2022	29,375	$ 31	399,826		(370,482)
Balance (in shares) at Sep. 30, 2022		31,490,053
Balance at Mar. 31, 2022	27,084	$ 31	444,283		(417,230)
Balance (in shares) at Mar. 31, 2022		31,477,053
Stock-based compensation expense	346		346
Net income (loss)	51,632				51,632
Balance at Jun. 30, 2022	79,062	$ 31	444,629		(365,598)
Balance (in shares) at Jun. 30, 2022		31,477,053
Stock-based compensation expense	224		224
Issuance of common stock from stock grants and option exercises	4		4
Issuance of common stock from stock grants and option exercises, shares		13,000
Cash dividends paid ($1.43 per share)	(45,031)		(45,031)
Net income (loss)	(4,884)				(4,884)
Balance at Sep. 30, 2022	$ 29,375	$ 31	$ 399,826		$ (370,482)
Balance (in shares) at Sep. 30, 2022		31,490,053