Earnings Per Share - Summary of Reconciliation of Basic and Diluted Net Earnings (loss) Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Share [Abstract]
Net income attributable to stockholders of Advantage Solutions Inc.	$ 3,371	$ 6,121	$ 22,336	$ 6,005
Weighted average common shares-basic	318,418,746	318,464,596	318,103,452	318,035,355
Basic earnings per common share	$ 0.01	$ 0.02	$ 0.07	$ 0.02
Change in fair value of warrant liability	$ 0	$ (7,059)	$ 0	$ (1,553)
Numerator for diluted earnings per share	$ 3,371	$ (938)	$ 22,336	$ 4,452
Basic	318,418,746	318,464,596	318,103,452	318,035,355
Performance and Restricted Stock Units	99,902	3,457,299	444,169	3,207,047
Warrants	0	1,276,669	0	638,335
Employee stock purchase plan and stock options	596,217	95,709	372,104	78,216
Weighted average common shares - diluted	319,114,865	323,294,273	318,919,725	321,958,953
Diluted earnings (loss) per common share	$ 0.01	$ 0.00	$ 0.07	$ 0.01