Commitments and Contingencies (Details) - TOI Parent Inc.	9 Months Ended	12 Months Ended
Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($) item
Commitments and Contingencies
Number of rental agreements for property	49	43
Number of rental agreements for medical equipment classified as capital leases	4	4
Accrued a loss contingency for a legal matter related to an employee lawsuit	$ 350,000	$ 350,000

Amount of loss contingency liability.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant