Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-In Capital	Other Comprehensive Income	Accumulated Deficit	Total ClearSign Technologies Corp. Stockholders' Equity	Noncontrolling Interest	Total
Balance at the beginning at Dec. 31, 2020	$ 3	$ 84,411		$ (74,874)	$ 9,540	$ 1	$ 9,541
Balances (in shares) at Dec. 31, 2020	30,077
Shares issued upon exercise of options ($1.90 per share)		2			2		2
Shares issued upon exercise of options ($1.90 per share) (in shares)	1
Shares issued upon exercise of options ($3.80 per share)		36			36		36
Shares issued upon exercise of options ($3.80 per share) (in shares)	9
Shares issued upon exercise of options ($1.21 per share)		4			4		4
Shares issued upon exercise of options ($1.21 per share) (in shares)	3
Shares issued upon exercise of warrants ($1.80 per share)		67			67		67
Shares issued upon exercise of warrants ($1.80 per share) (in shares)	38
Fair value of stock options issued for board service		210			210		210
Fair value of stock issued in payment of accrued compensation		217			217		217
Fair value of stock issued in payment of accrued compensation (in shares)	64
Share based compensation		410			410		410
Proceeds receivable from At-The Market issuance		(1,076)			(1,076)		(1,076)
Shares issued through use of At The Market issuance		4,469			4,469		4,469
Shares issued through use of At The Market issuance (in shares)	941
Shares issued for services		9			9		9
Shares issued for services (in shares)	4
Net loss				(2,021)	(2,021)		(2,021)
Balance at the end at Mar. 31, 2021	$ 3	88,759		(76,895)	11,867	$ 1	11,868
Balances (in shares) at Mar. 31, 2021	31,137
Balance at the beginning at Dec. 31, 2021	$ 3	91,035	$ 9	(82,765)	8,282		8,282
Balances (in shares) at Dec. 31, 2021	31,582
Fair value of stock issued in payment of accrued compensation		95			95		95
Fair value of stock issued in payment of accrued compensation (in shares)	66
Share based compensation		80			80		80
Share based compensation (in shares)	3
Shares issued upon exercise of options ($2.93 per share) (in shares)	3
Shares issued upon exercise of options ($0.89 per share) (in shares)	1
Fair value of stock options granted in payment of accrued compensation		12			12		12
Shares issued through use of At The Market issuance		578			578		578
Shares issued through use of At The Market issuance (in shares)	496
Shares issued for services		7			7		7
Shares issued for services (in shares)	4
Net loss				(1,490)	(1,490)		(1,490)
Balance at the end at Mar. 31, 2022	$ 3	$ 91,807	$ 9	$ (84,255)	$ 7,564		$ 7,564
Balances (in shares) at Mar. 31, 2022	32,155