Unaudited Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenues:
Total revenues	$ 15,900	$ 27,658	$ 52,562	$ 98,386
Transaction-based expenses:
Transaction-based expenses	(86)	(582)	(397)	(3,174)
Total revenues, less transaction-based expenses	15,814	27,076	52,165	95,212
Operating expenses:
Compensation and benefits	44,040	22,880	115,064	70,737
Professional services	3,799	2,987	11,169	9,791
Acquisition-related transaction costs	821	71	5,219	163
Advertising and market development	928	1,134	3,873	2,979
Rent and occupancy	1,097	914	3,803	2,711
Technology and communications	3,536	2,259	8,368	5,839
General and administrative	2,601	1,139	7,373	3,127
Depreciation and amortization	1,428	1,385	4,531	4,137
Total operating expenses	58,250	32,769	159,400	99,484
Operating loss	(42,436)	(5,693)	(107,235)	(4,272)
Interest and other income (expenses):
Interest income (expenses), net	874	11	1,161	(2,323)
Change in fair value of warrant liabilities	25,210	737	19,808	(5,575)
Other income, net	202	74	731	230
Total interest income (expenses) and other income (expenses)	26,286	822	21,700	(7,668)
Loss before provision for income taxes	(16,150)	(4,871)	(85,535)	(11,940)
Provision for income taxes	48	203	206	199
Net loss	(16,198)	(5,074)	(85,741)	(12,139)
Net loss attributable to Forge Global Holdings, Inc.	$ (16,198)	$ (5,074)	$ (85,741)	$ (12,139)
Earnings Per Share [Abstract]
Basic (in dollars per share)	$ (0.10)	$ (0.10)	$ (0.64)	$ (0.22)
Diluted (in dollars per share)	$ (0.12)	$ (0.10)	$ (0.66)	$ (0.22)
Weighted-average shares used in computing net loss per share attributable to Forge Global Holdings, Inc. common stockholders:
Basic (in shares)	169,838,778	51,450,791	134,683,950	55,147,414
Diluted (in shares)	170,209,256	51,450,791	135,960,612	55,147,414
Placement fees
Revenues:
Total revenues	$ 8,227	$ 22,940	$ 33,763	$ 83,394
Custodial administration fees
Revenues:
Total revenues	$ 7,673	$ 4,718	$ 18,799	$ 14,992