Capital Stock and Stockholders' Deficit - Schedule of Preferred Stock Details Prior to Business Combination (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Preferred Stock Authorized	100,000,000	100,000,000
Preferred Stock Issued	0	0
Preferred Stock Outstanding	0	0
Legacy Allurion
Class of Stock [Line Items]
Preferred Stock Authorized	21,029,888
Preferred Stock Issued	19,921,042
Preferred Stock Outstanding	19,921,042
Carrying Value	$ 97,216
Series A Preferred Stock | Legacy Allurion
Class of Stock [Line Items]
Preferred Stock Authorized	2,276,786
Preferred Stock Issued	2,276,786
Preferred Stock Outstanding	2,276,786
Carrying Value	$ 1,542
Series A-1 Preferred Stock | Legacy Allurion
Class of Stock [Line Items]
Preferred Stock Authorized	1,513,028
Preferred Stock Issued	1,486,048
Preferred Stock Outstanding	1,486,048
Carrying Value	$ 2,842
Series B Preferred Stock | Legacy Allurion
Class of Stock [Line Items]
Preferred Stock Authorized	2,298,929
Preferred Stock Issued	2,245,515
Preferred Stock Outstanding	2,245,515
Carrying Value	$ 5,253
Series C Preferred Stock | Legacy Allurion
Class of Stock [Line Items]
Preferred Stock Authorized	8,113,616
Preferred Stock Issued	7,927,446
Preferred Stock Outstanding	7,927,446
Carrying Value	$ 39,122
Series D-1 Preferred Stock | Legacy Allurion
Class of Stock [Line Items]
Preferred Stock Authorized	1,684,565
Preferred Stock Issued	842,283
Preferred Stock Outstanding	842,283
Carrying Value	$ 9,614
Series D-2 Preferred Stock | Legacy Allurion
Class of Stock [Line Items]
Preferred Stock Authorized	3,644,616
Preferred Stock Issued	3,644,616
Preferred Stock Outstanding	3,644,616
Carrying Value	$ 24,054
Series D-3 Preferred Stock | Legacy Allurion
Class of Stock [Line Items]
Preferred Stock Authorized	1,498,348
Preferred Stock Issued	1,498,348
Preferred Stock Outstanding	1,498,348
Carrying Value	$ 14,789