Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenue	$ 992,584	$ 421,712	$ 32,528
Cost of revenue	215,533	89,807	14,107
Gross profit	777,051	331,905	18,421
Operating expenses:
Research and development	24,219	11,580	6,537
Selling and marketing	24,439	14,952	5,898
General and administrative	50,732	15,215	6,414
Amortization of intangible assets	1,708
Total operating expenses	101,098	41,747	18,849
Operating income (loss)	675,953	290,158	(428)
Interest and other income, net	1,347	1,526	837
Income before income taxes, equity loss in investee and gain (loss) on equity-method investments	677,300	291,684	409
Provision for income taxes	174,795	72,532	43
Income before equity loss in investee and gain (loss) on equity-method investments	502,505	219,152	366
Equity loss in investee		(488)	(777)
Gain (loss) on equity-method investments	3,734	(4,354)
Net income (loss) from consolidated operations	506,239	214,310	(411)
Net loss attributable to noncontrolling interests	1,125
Net income (loss) attributable to Fulgent	$ 507,364	$ 214,310	$ (411)
Net income (loss) per common share attributable to Fulgent:
Basic	$ 17.25	$ 9.44	$ (0.02)
Diluted	$ 16.38	$ 8.91	$ (0.02)
Weighted-average common shares:
Basic	29,408	22,694	18,709
Diluted	30,976	24,056	18,709