Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Debt - Long-term debt, net of unamortized debt issuance costs and current portion (Details) - USD ($)	Sep. 30, 2021	Feb. 12, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt
Unamortized debt issuance costs	$ 229,725
TOI Parent Inc.
Debt
Total long-term debt			$ 7,218,750
Unamortized debt issuance costs	229,725		282,512	$ 0
Current portion	4,895,275	$ 149,398	375,000
Long-term debt, net of unamortized debt issuance costs and current portion			6,561,238
TOI Parent Inc. \| Variable Rate Revolving Credit Facility Term Loan, interest at LIBOR plus applicable margin, due February 26, 2025
Debt
Total long-term debt	5,125,000		7,218,750
Unamortized debt issuance costs	$ 229,725		$ 282,512