Share-Based Compensation - RSAs Additional Details (Details) - TOI Parent Inc. - Restricted Stock Awards - USD ($)	6 Months Ended	12 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award
Compensation costs recognized	$ 0	$ 0	$ 0	$ 0
Unrecognized compensation expense	$ 0	$ 0	1,159,977	$ 453,269
Liability associated with the bonus awards			$ 0
Shares holdings issued			188		0
Shares, Issued	0		0

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable within one year (or the operating cycle, if longer). Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Number of shares of stock issued as of the balance sheet date, including shares that had been issued and were previously outstanding but which are now held in the treasury.

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