Fair Value Measurements	9 Months Ended
Fair Value Measurements	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Financial Instruments The carrying value of our outstanding term loan as of September 30, 2021 (excluding unamortized discounts and debt issuance costs of $5.4 million) was $487.3 million compared to its fair value of $486.7 million. The carrying value of our outstanding term loan as of December 31, 2020 (excluding unamortized discounts and debt issuance costs of $6.5 million) was $491.1 million compared to its fair value of $489.9 million. Our estimates of fair value are based on a discounted cash flow model and an indicative quote using unobservable inputs, primarily, our risk-adjusted credit spread, which represents a Level 3 measurement. We have interest rate swap agreements designated as cash flow hedges and are measured at fair value based on inputs other than quoted market prices that are observable, which represents a Level 2 measurement. See Note K - “Debt and Other Obligations” and Note M - “Derivative Financial Instruments” for further information. We believe that the carrying value of the Seller Notes and the deferred payment obligation approximates their fair values based on a discounted cash flow model using unobservable inputs, primarily, our credit spread for subordinated debt, which represents a Level 3 measurement. The carrying value of our outstanding Seller Notes and the deferred payment obligation issued in connection with past acquisitions as of September 30, 2021 and December 31, 2020 was $21.8 million and $14.6 million, net of unamortized discounts of $0.8 million and $0.9 million, respectively.

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.