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Merger and Financing - Merger with Histogenics (Details) - USD ($)					1 Months Ended
	Dec. 31, 2019	Oct. 04, 2019	Sep. 27, 2019	May 08, 2019	Jan. 31, 2018	Sep. 26, 2019	Dec. 31, 2018
Merger and Financing
Cash and cash equivalents	$ 7,444,052						$ 1,628,136
Accounts payable	(1,895,613)						$ (3,277,525)
Asset purchase agreement, cash consideration	8,500,000
Histogenics
Merger and Financing
Acquisition cost incurred			$ 4,900,000
Acquisition cost paid in cash			2,600,000
Acquisition cost paid with equity			2,300,000
Cash and cash equivalents			302,000
Asset held for sale			7,000,000
Accounts payable			(1,106,000)
Net assets acquired			$ 6,196,000
Asset purchase agreement, cash consideration				$ 6,500,000
Percentage of purchase price increase per month		10.00%
Histogenics \| Level 2
Merger and Financing
Quoted price of assets held for sale of NeoCart	7,000,000.0
Neocart \| Level 2
Merger and Financing
Quoted price of assets held for sale of NeoCart	$ 7,000,000.0
Former Ocugen equity holders \| Histogenics
Merger and Financing
Ownership (as a percent)			84.25%
Stockholders of Histogenics immediately before the Merger \| Histogenics
Merger and Financing
Ownership (as a percent)						15.75%
Histogenics
Merger and Financing
Upfront cash payment received for license granted to MEDINET					$ 10,000,000.0