Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	2019 Equity Distribution Agreement	September 2020 Equity Distribution Agreement	November 2020 Equity Distribution Agreement	Stockholders' Equity	Stockholders' Equity 2019 Equity Distribution Agreement	Stockholders' Equity September 2020 Equity Distribution Agreement	Stockholders' Equity November 2020 Equity Distribution Agreement	Additional Paid-In Capital	Additional Paid-In Capital 2019 Equity Distribution Agreement	Additional Paid-In Capital September 2020 Equity Distribution Agreement	Additional Paid-In Capital November 2020 Equity Distribution Agreement	Accumulated Other Comprehensive Income (Loss)	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit) Cumulative Effect, Period of Adoption, Adjustment	Fulgent Stockholders' Equity	Fulgent Stockholders' Equity Cumulative Effect, Period of Adoption, Adjustment	Fulgent Stockholders' Equity 2019 Equity Distribution Agreement	Fulgent Stockholders' Equity September 2020 Equity Distribution Agreement	Fulgent Stockholders' Equity November 2020 Equity Distribution Agreement	Noncontrolling Interest
Beginning Balance at Dec. 31, 2019	$ 82,777					$ 2				$ 146,058				$ 146	$ (63,429)		$ 82,777
Beginning Balance, Shares at Dec. 31, 2019						21,483
Equity-based compensation	8,157									8,157							8,157
Exercise of common stock options	104									104							104
Exercise of common stock options, Shares						56
Restricted stock awards, Shares						655
Issuance of common stock			$ 42,655	$ 122,103	$ 99,051			$ 1			$ 42,655	$ 122,102	$ 99,051						$ 42,655	$ 122,103	$ 99,051
Issuance of common stock, Shares							1,108	2,846	2,034
Common stock withholding for employee tax obligations	(62)									(62)							(62)
Common stock withholding for employee tax obligations, Shares						(4)
Other comprehensive gain (loss), net	292													292			292
Net income (loss)	214,310														214,310		214,310
Ending Balance at Dec. 31, 2020	569,387	$ (887)				$ 3				418,065				438	150,881	$ (887)	569,387	$ (887)
Ending Balance, Shares at Dec. 31, 2020						28,178
Equity-based compensation	15,882									15,882							15,882
Exercise of common stock options	86									86							86
Exercise of common stock options, Shares						76
Restricted stock awards, Shares						836
Issuance of common stock					$ 72,030								$ 72,030								$ 72,030
Issuance of common stock, Shares									1,111
Common stock withholding for employee tax obligations	(4,155)									(4,155)							(4,155)
Common stock withholding for employee tax obligations, Shares						(41)
Cumulative tax effect of accounting change	239														239		239
Noncontrolling interest assumed related to acquisitions	8,151																					$ 8,151
Other comprehensive gain (loss), net	(1,092)													(1,197)			(1,197)					105
Net income (loss)	506,239														507,364		507,364					(1,125)
Ending Balance at Dec. 31, 2021	$ 1,165,880					$ 3				501,908				(759)	657,597		1,158,749					7,131
Ending Balance, Shares at Dec. 31, 2021	30,160					30,160
Equity-based compensation	$ 32,640									32,640							32,640
Exercise of common stock options	31									31							31
Exercise of common stock options, Shares						5
Restricted stock awards, Shares						699
Common stock withholding for employee tax obligations	(1,768)									(1,768)							(1,768)
Common stock withholding for employee tax obligations, Shares						(32)
Repurchase of common stock	$ (74,337)									(74,337)							(74,337)
Repurchase of common stock, Shares	(1,800)					(1,810)
Common stock issued in a business combination	$ 28,111									28,111							28,111
Common stock issued in a business combination, Shares						416
Other comprehensive gain (loss), net	(22,605)													(20,144)			(20,144)					(2,461)
Net income (loss)	141,923														143,403		143,403					(1,480)
Ending Balance at Dec. 31, 2022	$ 1,269,875					$ 3				$ 486,585				$ (20,903)	$ 801,000		$ 1,266,685					$ 3,190
Ending Balance, Shares at Dec. 31, 2022	31,248					29,438