Condensed Consolidated Statements of Stockholders' (Deficit) Equity - USD ($) $ in Thousands	Total	At-the-Market	Common Stock	Common Stock At-the-Market	Additional Paid-in Capital	Additional Paid-in Capital At-the-Market	Accumulated Deficit	Accumulated Other Comprehensive Income	Total ImmunityBio Stockholders’ Deficit	Total ImmunityBio Stockholders’ Deficit At-the-Market	Noncontrolling Interests
Beginning balance (in shares) at Dec. 31, 2019			371,976,995
Beginning balance at Dec. 31, 2019	$ 16,326		$ 37		$ 1,406,002		$ (1,393,280)	$ (87)	$ 12,672		$ 3,654
Increase (Decrease) in Statements of Stockholders’ Deficit [Roll Forward]
Issuance of common stock, net (in shares)			8,521,500
Issuance of common stock, net	86,302		$ 1		86,301				86,302
Stock-based compensation expense	1,516				1,516				1,516
Exercise of stock options, (in shares)			1,142,273
Exercise of stock options	917				917				917
Vesting of restricted stock units (RSUs) (in shares)			642,236
Net share settlement for RSUs vesting (in shares)			(173,830)
Net share settlement for RSUs vesting	(485)				(485)				(485)
Other comprehensive income (loss), net of tax	(34)							(34)	(34)
Net loss	(155,614)						(154,080)		(154,080)		(1,534)
Ending balance (in shares) at Sep. 30, 2020			382,109,174
Ending balance at Sep. 30, 2020	(51,072)		$ 38		1,494,251		(1,547,360)	(121)	(53,192)		2,120
Beginning balance (in shares) at Jun. 30, 2020			381,280,749
Beginning balance at Jun. 30, 2020	14,379		$ 38		1,493,486		(1,481,757)	(75)	11,692		2,687
Increase (Decrease) in Statements of Stockholders’ Deficit [Roll Forward]
Issuance of common stock, net	19				19				19
Stock-based compensation expense	714				714				714
Exercise of stock options, (in shares)			883,256
Exercise of stock options	353				353				353
Vesting of restricted stock units (RSUs) (in shares)			83,260
Net share settlement for RSUs vesting (in shares)			(138,091)
Net share settlement for RSUs vesting	(321)				(321)				(321)
Other comprehensive income (loss), net of tax	(46)							(46)	(46)
Net loss	(66,170)						(65,603)		(65,603)		(567)
Ending balance (in shares) at Sep. 30, 2020			382,109,174
Ending balance at Sep. 30, 2020	$ (51,072)		$ 38		1,494,251		(1,547,360)	(121)	(53,192)		2,120
Beginning balance (in shares) at Dec. 31, 2020	382,243,142		382,243,142
Beginning balance at Dec. 31, 2020	$ (118,490)		$ 38		1,495,163		(1,615,131)	122	(119,808)		1,318
Increase (Decrease) in Statements of Stockholders’ Deficit [Roll Forward]
Issuance of common stock, net (in shares)				10,216,978
Issuance of common stock, net		$ 136,948		$ 1		$ 136,947				$ 136,948
Stock-based compensation expense	$ 47,001				47,001				47,001
Exercise of stock options, (in shares)	1,747,962		1,626,300
Exercise of stock options	$ 5,110				5,110				5,110
Vesting of restricted stock units (RSUs) (in shares)			621,364
Net share settlement for RSUs vesting (in shares)			(198,089)
Net share settlement for RSUs vesting	(3,584)				(3,584)				(3,584)
Sale of assets to an entity under common control (Note 8)	1,435				1,435				1,435
Other comprehensive income (loss), net of tax	(69)							(69)	(69)
Net loss	$ (258,295)						(255,531)		(255,531)		(2,764)
Ending balance (in shares) at Sep. 30, 2021	394,509,695		394,509,695
Ending balance at Sep. 30, 2021	$ (189,944)		$ 39		1,682,072		(1,870,662)	53	(188,498)		(1,446)
Beginning balance (in shares) at Jun. 30, 2021			390,347,740
Beginning balance at Jun. 30, 2021	(158,585)		$ 39		1,625,018		(1,783,033)	37	(157,939)		(646)
Increase (Decrease) in Statements of Stockholders’ Deficit [Roll Forward]
Issuance of common stock, net (in shares)				3,796,537
Issuance of common stock, net		$ 42,061				$ 42,061				$ 42,061
Stock-based compensation expense	13,840				13,840				13,840
Exercise of stock options, (in shares)			176,196
Exercise of stock options	678				678				678
Vesting of restricted stock units (RSUs) (in shares)			285,280
Net share settlement for RSUs vesting (in shares)			(96,058)
Net share settlement for RSUs vesting	(960)				(960)				(960)
Sale of assets to an entity under common control (Note 8)	1,435				1,435				1,435
Other comprehensive income (loss), net of tax	16							16	16
Net loss	$ (88,429)						(87,629)		(87,629)		(800)
Ending balance (in shares) at Sep. 30, 2021	394,509,695		394,509,695
Ending balance at Sep. 30, 2021	$ (189,944)		$ 39		$ 1,682,072		$ (1,870,662)	$ 53	$ (188,498)		$ (1,446)