Earnings per Share - Summary of Earnings Per Share (Detail) - USD ($)	3 Months Ended						12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net loss							$ (12,850,301)	$ (8,503,948)
Add deemed contribution from the redemption of preferred stock			$ 7,448,879				0	7,448,879
Less deemed dividend of beneficial conversion feature		$ (825,366)					(825,366)	0
Less deemed dividend on warrant discount	$ (645,939)	$ (179,427)					(825,366)	0
Net loss attributable to Laird Superfood, Inc. common stockholders							$ (14,501,033)	$ (1,055,069)
Weighted average shares outstanding- basic			4,045,056	3,592,735	3,520,338	3,509,009	5,546,078	3,668,050
Dilutive securities
Weighted average shares outstanding- diluted			5,532,032	3,592,735	3,520,338	3,509,009	5,546,078	3,668,050
Common stock options and restricted stock awards excluded due to anti-dilutive effect							945,027	2,492,375
Basic and diluted:
Net loss per share (basic)			$ 1.31	$ (0.66)	$ (0.64)	$ (0.49)	$ (2.61)	$ (0.29)
Net loss per share (diluted)			$ 0.96	$ (0.66)	$ (0.64)	$ (0.49)	$ (2.61)	$ (0.29)