Warrants to Purchase Common Stock or CDIs (Details) - USD ($) $ / shares in Units, $ in Millions			1 Months Ended	3 Months Ended
	Sep. 04, 2020	May 04, 2016	Aug. 21, 2019	Mar. 31, 2021	Mar. 31, 2020
Warrants to Purchase Common Stock or CDIs (Details) [Line Items]
Consultant warrant to purchase		28,532
Exercise price per share		$ 0.64
Warrants expiry date		May 04, 2021
Warrants description			GI Dynamics and Crystal Amber entered into a securities purchase agreement (“SPA”) for a total funding of up to approximately $10 million (the “August 2019 SPA”) comprised of the scheduled exercise of the 2018 Warrant, the March 2019 Warrant, and the May 2019 Warrant as detailed above and the sale of an Unsecured Convertible Note for up to approximately $4.6 million (the “August 2019 Note”), which included an agreement to issue a warrant (the “August 2019 Warrant”) to purchase up to 229,844,650 CDIs (representing 4,596,893 shares of common stock) for an exercise price of $0.02 per CDI. On December 16, 2019, stockholder approval for the warrant to be issued was obtained and it was issued on January 13, 2020 together with the funding of the August 2019 Note.
Expected volatility rate				111.40%	164.90%
Expected term				6 years 3 months	5 years 306 days
Risk-free interest rate				0.70%	0.90%
Warrant [Member]
Warrants to Purchase Common Stock or CDIs (Details) [Line Items]
Estimated fair value			$ 2.3
Expected volatility rate			141.00%
Expected term			5 years
Risk-free interest rate			1.65%
Series A Preferred Stock [Member]
Warrants to Purchase Common Stock or CDIs (Details) [Line Items]
Sale of shares value	$ 10.0

GI DYNAMICS, INC. 10-Q