Unaudited Condensed Consolidated Statements of Stockholders' Equity - USD ($)	Preferred Stock	Common Stock	Additional Paid-in Capital	Treasury Stock	Accumulated Other Comprehensive Income /(Loss)	Accumulated Deficit	Total
Balance at Dec. 31, 2020	$ 0	$ 1,240,000	$ 658,246,000	$ (8,034,000)	$ 589,000	$ (570,501,000)	$ 81,540,000
Balance (in shares) at Dec. 31, 2020	0	12,394,271
Issuance of common stock pursuant to financing agreements		$ 159,000	32,341,000				32,500,000
Issuance of common stock pursuant to financing agreements (in shares)		1,585,365
Stock issuance costs	$ 0	$ 0	(2,019,000)	0	0	0	(2,019,000)
Stock-based compensation expense, net of forfeitures	0	0	1,998,000	0	0	0	1,998,000
Foreign currency translation adjustment	0	0	0	0	(104,000)	0	(104,000)
Net loss attributable to CASI Pharmaceuticals, Inc.	0	0	(548,000)	0	0	(13,335,000)	(13,883,000)
Balance at Mar. 31, 2021		$ 1,399,000	690,018,000	(8,034,000)	485,000	(583,836,000)	100,032,000
Balance (in shares) at Mar. 31, 2021		13,979,636
Balance at Dec. 31, 2020	$ 0	$ 1,240,000	658,246,000	(8,034,000)	589,000	(570,501,000)	81,540,000
Balance (in shares) at Dec. 31, 2020	0	12,394,271
Net loss attributable to CASI Pharmaceuticals, Inc.							(20,829,000)
Balance at Jun. 30, 2021	$ 0	$ 1,399,000	690,539,000	(8,034,000)	1,159,000	(590,263,000)	94,800,000
Balance (in shares) at Jun. 30, 2021	0	13,979,636
Balance at Mar. 31, 2021		$ 1,399,000	690,018,000	(8,034,000)	485,000	(583,836,000)	100,032,000
Balance (in shares) at Mar. 31, 2021		13,979,636
Stock-based compensation expense, net of forfeitures			1,040,000				1,040,000
Foreign currency translation adjustment					674,000		674,000
Net loss attributable to CASI Pharmaceuticals, Inc.			(519,000)			(6,427,000)	(6,946,000)
Balance at Jun. 30, 2021	$ 0	$ 1,399,000	690,539,000	(8,034,000)	1,159,000	(590,263,000)	94,800,000
Balance (in shares) at Jun. 30, 2021	0	13,979,636
Balance at Dec. 31, 2021	$ 0	$ 1,399,000	694,826,000	(8,034,000)	1,954,000	(605,643,000)	84,502,000
Balance (in shares) at Dec. 31, 2021	0	13,979,624
Repurchase and retirement of common stock		$ (26,000)	(1,940,000)	(1,034,000)			$ (3,000,000)
Repurchase and retirement of common stock (in shares)		(373,494)					(3,734,992)
Stock-based compensation expense, net of forfeitures	$ 0	$ 0	1,908,000	0	0	0	$ 1,908,000
Foreign currency translation adjustment	0	0	0	0	175,000	0	175,000
Net loss attributable to CASI Pharmaceuticals, Inc.	0	0	(613,000)	0	0	(7,983,000)	(8,596,000)
Balance at Mar. 31, 2022		$ 1,373,000	694,181,000	(9,068,000)	2,129,000	(613,626,000)	74,989,000
Balance (in shares) at Mar. 31, 2022		13,606,130
Balance at Dec. 31, 2021	$ 0	$ 1,399,000	694,826,000	(8,034,000)	1,954,000	(605,643,000)	84,502,000
Balance (in shares) at Dec. 31, 2021	0	13,979,624
Net loss attributable to CASI Pharmaceuticals, Inc.							(16,276,000)
Balance at Jun. 30, 2022	$ 0	$ 1,373,000	695,369,000	(9,068,000)	(160,000)	(620,571,000)	66,943,000
Balance (in shares) at Jun. 30, 2022	0	13,606,130
Balance at Mar. 31, 2022		$ 1,373,000	694,181,000	(9,068,000)	2,129,000	(613,626,000)	74,989,000
Balance (in shares) at Mar. 31, 2022		13,606,130
Stock-based compensation expense, net of forfeitures			1,923,000	0	0	0	1,923,000
Foreign currency translation adjustment				0	(2,289,000)	0	(2,289,000)
Net loss attributable to CASI Pharmaceuticals, Inc.			(735,000)	0	0	(6,945,000)	(7,680,000)
Balance at Jun. 30, 2022	$ 0	$ 1,373,000	$ 695,369,000	$ (9,068,000)	$ (160,000)	$ (620,571,000)	$ 66,943,000
Balance (in shares) at Jun. 30, 2022	0	13,606,130