Organization and Summary of Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for fair presentation of the Company's financial position and results of operations have been included. The Company’s fiscal year ends on December 31 and interim results are not necessarily indicative of results for a full year or any other interim period. The information contained in these condensed consolidated financial statements should be read in conjunction with the Company’s consolidated financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2019 (the "2019 Annual Report on Form 10-K").
Principles of Consolidation	The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, as well as interests in partnerships and limited liability companies controlled by the Company through its ownership of a majority voting interest or other rights granted to the Company by contract to manage and control the affiliate's business. All significant intercompany balances and transactions are eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and footnotes. Examples include, but are not limited to, estimates of accounts receivable allowances, professional and general liabilities and the estimate of deferred tax assets or liabilities. Actual results could differ from those estimates.
Variable Interest Entities	Variable Interest EntitiesThe condensed consolidated financial statements include the accounts of variable interest entities ("VIE") in which the Company is the primary beneficiary under the provisions of the Financial Accounting Standards Board's ("FASB") Accounting Standards Codification 810, "Consolidation". The Company has the power to direct the activities that most significantly impact a VIEs economic performance. Additionally, the Company would absorb the majority of the expected losses from any of these entities should such expected losses occur.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The fair value of a financial instrument is the amount at which the instrument could be exchanged in an orderly transaction between market participants to sell the asset or transfer the liability. The Company uses fair value measurements based on inputs classified into the following hierarchy: •Level 1: Unadjusted quoted prices in active markets for identical assets or liabilities. •Level 2: Inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly. These may include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. •Level 3: Unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions, depending on the nature of the item being valued. The carrying amounts reported in the condensed consolidated balance sheets for cash and cash equivalents, accounts receivable, restricted invested assets and accounts payable approximate their fair values under Level 3 inputs. The fair values in the table above were based on a Level 2 inputs using quoted prices for identical liabilities in inactive markets. The carrying amounts related to the Company's other long-term debt obligations, including finance lease obligations, approximate their fair values under Level 3 inputs. The Company has entered into certain interest rate swap agreements (see Note 7. "Derivatives and Hedging Activities"). The fair value of these derivative instruments was $65.3 million and $50.7 million at September 30, 2020 and December 31, 2019, respectively, and was included in other long-term liabilities in the condensed consolidated balance sheets. The fair value of these derivative financial instruments was based on a quoted market price, or a Level 2 input.
Revenues	Revenues The Company's revenues generally relate to contracts with patients in which the performance obligations are to provide health care services. The Company recognizes revenues in the period in which our obligations to provide health care services are satisfied and reports the amount that reflects the consideration the Company expects to be entitled to receive. The contractual relationships with patients, in most cases, also involve a third-party payor (e.g., Medicare, Medicaid and private insurance organizations, including plans offered through the health insurance exchanges) and the transaction prices for the services provided are dependent upon the terms provided by or negotiated with the third-party payors. The payment arrangements with third-party payors for the services provided to the related patients typically specify payments at amounts less than the Company's standard charges. The Company continually reviews the contractual estimation process to consider and incorporate updates to laws and regulations and the frequent changes in managed care contractual terms resulting from contract renegotiations and renewals. Patient service revenues. This revenue is related to charging facility fees in exchange for providing patient care. The fee charged for health care procedures performed in surgical facilities varies depending on the type of service provided, but usually includes all charges for usage of an operating room, a recovery room, special equipment, medical supplies, nursing staff and medications. The fee does not normally include professional fees charged by the patient’s surgeon, anesthesiologist or other attending physician, which are billed directly by such physicians to the patient or third-party payor. However, in several surgical facilities, the Company charges for anesthesia services. Ancillary service revenues include fees for patient visits to the Company's physician practices, pharmacy services and diagnostic tests ordered by physicians. Patient service revenues are recognized as performance obligations are satisfied. Performance obligations are based on the nature of services provided. Typically, the Company recognizes revenue at a point in time in which services are rendered and the Company has no obligation to provide further patient services. As the Company primarily performs outpatient procedures, performance obligations are generally satisfied same day and revenue is recognized on the date of service. The Company determines the transaction price based on gross charges for services provided, net of estimated contractual adjustments and discounts from third-party payors. The Company estimates its contractual adjustments and discounts based on contractual agreements, its discount policies and historical experience. Changes in estimated contractual adjustments and discounts are recorded in the period of change. Other service revenues. Optical service revenues consist of handling charges billed to the members of the Company's optical products purchasing organization. The Company's optical products purchasing organization negotiates volume buying discounts with optical products manufacturers. The buying discounts and any handling charges billed to the members of the buying group represent the revenue recognized for financial reporting purposes. The Company satisfies the performance obligation and recognizes revenue when the orders are shipped to members. The Company bases its estimates for sales returns and discounts on historical experience and has not experienced significant fluctuations between estimated and actual return activity and discounts given. Other revenues include management and administrative service fees derived from the non-consolidated facilities that the Company accounts for under the equity method, management of surgical facilities in which it does not own an interest, and management services provided to physician practices for which the Company is not required to provide capital or additional assets. These agreements typically require the Company to provide recurring management services over a multi-year period, which are billed and collected on a monthly basis. The fees derived from these management arrangements are based on a predetermined percentage of the revenues of each facility or practice and are recognized in the period in which management services are rendered and billed.
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. The Company maintains its cash and cash equivalent balances at high credit quality financial institutions. Cash, cash equivalents and restricted cash reported within the consolidated statement of cash flows includes $0.3 million of restricted investments, which are reflected in other long-term assets in the consolidated balance sheet at both September 30, 2020 and December 31, 2019. These restricted investments represent restricted cash held in accordance with the provisions of a long-term operating lease agreement held as security for performance under the Company's covenants and obligations within the agreement through January 2024.
Accounts Receivable	Accounts Receivable Accounts receivable from third-party payors are recorded net of estimated implicit price concessions, which are estimated based on the historical trend of the Company's surgical facilities’ cash collections and contractual write-offs, established fee schedules, relationships with payors and procedure statistics. While changes in estimated reimbursement from third-party payors remain a possibility, the Company expects that any such changes would be minimal and, therefore, would not have a material effect on its financial condition or results of operations. Accounts receivable consists of receivables from federal and state agencies (under the Medicare and Medicaid programs), private insurance organizations, employers and patients. Management recognizes that revenues and receivables from government agencies are significant to the Company's operations, but it does not believe that there is significant credit risk associated with these government agencies. Concentration of credit risk with respect to other payors is limited because of the large number of such payors. As of September 30, 2020 and December 31, 2019, the Company had a net third-party Medicaid settlements liability of $15.7 million and $5.6 million, respectively, included in other current liabilities in the condensed consolidated balance sheets. The Company recognizes that final reimbursement of accounts receivable is subject to final approval by each third-party payor. However, because the Company has contracts with its third-party payors and also verifies insurance coverage of the patient before medical services are rendered, the amounts that are pending approval from third-party payors are not considered significant. Amounts are classified outside of self-pay if the Company has an agreement with the third-party payor or has verified a patient’s coverage prior to services rendered. The Company's policy is to collect co-payments and deductibles prior to providing medical services. Patient services of the Company are primarily non-emergency, which allows the surgical facilities to control the procedures for which third-party reimbursement is sought and obtained. The Company does not require collateral from self-pay patients. The Company's collection policies and procedures are based on the type of payor, size of claim and estimated collection percentage for each patient account. The operating systems used to manage patient accounts provide for an aging schedule in 30-day increments, by payor, physician and patient. The Company analyzes accounts receivable at each of its surgical facilities to ensure the proper collection and aged category. The operating systems generate reports that assist in the collection efforts by prioritizing patient accounts. Collection efforts include direct contact with third-party payors or patients, written correspondence and the use of legal or collection agency assistance, as required. The receivables related to the Company's optical products purchasing organization are recognized separately from patient accounts receivable, as discussed above, and are included in other current assets in the condensed consolidated balance sheets.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities The Company records all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain of its risk, even though hedge accounting does not apply or the Company elects not to apply hedge accounting. The Company made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio. The Company’s objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company primarily uses interest rate swaps as part of its interest rate risk management strategy. During 2020, such derivatives have been used to hedge the variable cash flows associated with existing variable-rate debt. For derivatives designated and that qualify as cash flow hedges of interest rate risk, the gain or loss on the derivative is recorded in accumulated other comprehensive income ("OCI") and subsequently reclassified into interest expense in the same period(s) during which the hedged transaction affects earnings, as documented at hedge inception in accordance with the Company’s accounting policy election. Amounts reported in accumulated OCI related to derivatives will be reclassified to interest expense as interest payments are made on the Company’s variable-rate debt.
Non-Controlling Interests—Redeemable	Non-Controlling Interests—Redeemable Each partnership and limited liability company through which the Company owns and operates its surgical facilities is governed by a partnership or operating agreement, respectively. In certain circumstances, the applicable partnership or operating agreements for the Company's surgical facilities provide that the facilities will purchase all of the physician limited partners’ or physician minority members’, as applicable, ownership if certain adverse regulatory events occur, such as it becoming illegal for the physician(s) to own an interest in a surgical facility, refer patients to a surgical facility or receive cash distributions from a surgical facility. The non-controlling interests—redeemable are reported outside of stockholders' equity in the condensed consolidated balance sheets.
Income Taxes	Income Taxes The Company uses the asset and liability method to account for income taxes. Under this method, deferred income tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. If a carryforward exists, the Company makes a determination as to whether the carryforward will be utilized in the future. A valuation allowance is established for certain carryforwards when their recoverability is deemed to be uncertain. The carrying value of the net deferred tax assets assumes that the Company will be able to generate sufficient future taxable income in certain tax jurisdictions, based on estimates and assumptions. If our expectations for future operating results on a consolidated basis or at the state jurisdiction level vary from actual results due to changes in health care regulations, general economic conditions, or other factors, we may need to adjust the valuation allowance, for all or a portion of our deferred tax assets. Our income tax expense in future periods will be reduced or increased to the extent of offsetting decreases or increases, respectively, in our valuation allowance in the period when the change in circumstances occurs. These changes could have a significant impact on our future earnings. The Company and certain of its subsidiaries file a consolidated federal income tax return. The partnerships, limited liability companies, and certain non-consolidated physician practice corporations also file separate income tax returns. The Company's allocable portion of each partnership's and limited liability company's income or loss is included in taxable income of the Company. The remaining income or loss of each partnership and limited liability company is allocated to the other owners. The Company's effective tax rate was 23.7% for the nine months ended September 30, 2020 compared to 18.5% for the nine months ended September 30, 2019. The higher effective tax rate for the 2020 period was primarily due to (a) discrete tax benefits of approximately $6.9 million attributable to the release of federal and state valuation allowances on the Company’s Internal Revenue Code Section 163(j) interest carryforwards as a result of the increase in deductible interest expense allowed under the CARES Act, and $5.0 million attributable to a portion of the payments under the Settlement Agreement, as defined in Note 10. "Commitments and Contingencies," being classified as "restitution" for income tax purposes; and (b) a discrete tax expense of approximately $5.0 million attributable to the Company's impairment of goodwill. Based upon the application of interim accounting guidance, the tax rate as a percentage of net income after income attributable to non-controlling interests will vary based upon the relative net income from period to period.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In March 2020, the FASB issued Accounting Standards Update (“ASU”) 2020-04 Reference Rate Reform (Topic 848). ASU 2020-04 contains practical expedients for reference rate reform related activities that impact debt, leases, derivatives and other contracts. The guidance in ASU 2020-04 is optional and may be elected over time as reference rate reform activities occur. During the nine months ended September 30, 2020, the Company elected to apply the hedge accounting expedients related to probability and the assessments of effectiveness for future London Interbank Offered Rate ("LIBOR") indexed cash flows to assume that the index upon which future hedged transactions will be based matches the index on the corresponding derivatives. Application of these expedients preserves the presentation of derivatives consistent with past presentation. The Company continues to evaluate the impact of the guidance and may apply other elections as applicable as additional changes in the market occur. In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses, which introduced a new model for recognizing credit losses on financial instruments based on an estimate of the current expected credit losses. The new current expected credit losses (“CECL”) model generally calls for the immediate recognition of all expected credit losses and applies to financial instruments and other assets, which is primarily applicable to accounts receivable for the Company. This ASU was effective for the Company on January 1, 2020. The adoption of this ASU did not have a material impact on its consolidated financial position and results of operations.
Goodwill	Goodwill represents the fair value of the consideration provided in an acquisition over the fair value of net assets acquired and is not amortized. Additions to goodwill include amounts resulting from new business combinations and incremental ownership purchases in the Company's subsidiaries. The Company tests its goodwill and indefinite-lived intangible assets for impairment at least annually, as of October 1, or more frequently if certain indicators arise. The Company tests for goodwill impairment at the reporting unit level, which is defined as one level below an operating segment. A detailed evaluation of potential impairment indicators was performed as of September 30, 2020, which specifically considered the volatility observed in the prices of the Company’s outstanding debt securities and common stock, as well as the decline in surgical case volumes following the emergence of the COVID-19 pandemic, all of which improved throughout the second and third quarters as states began to re-open and allow for non-emergent procedures. As of September 30, 2020, the Company has identified three reporting units, which include the following: 1) Surgical Facilities, 2) Ancillary Services, and 3) Alliance, which is a component of the Optical Services operating segment. On the basis of available evidence as of September 30, 2020, no indicators of impairment were identified for the Company's Surgical Facilities reporting unit. The Company did identify indicators of impairment related to its Ancillary Services and Alliance reporting units, including the impacts of the COVID-19 pandemic and the closure of its diagnostic laboratory (as discussed in Note 2. "Acquisitions and Disposals"). Based on the impairment indicators for these reporting units, the Company performed an impairment analysis as of September 30, 2020. The Company compares the carrying value of the net assets of the reporting unit to the estimated fair value of the reporting unit. To determine the fair value of the reporting units, the Company obtained valuations at the reporting unit level prepared by third-party valuation specialists which utilized a combination of the income and market approaches. The discounted cash flow model is projected based on a year-by-year assessment that considers historical results, estimated market conditions, internal projections, and relevant publicly available statistics. Determining fair value requires the exercise of significant judgment, including assumptions about appropriate discount rates, perpetual growth rates and the amount and timing of expected future cash flows. The significant judgments are typically based upon Level 3 inputs, generally defined as unobservable inputs representing the Company's own assumptions. The cash flows employed in the discounted cash flow analysis are based on the Company's most recent budgets and business plans aligned with provided guidance and, when applicable, various growth rates are assumed for years beyond the current business plan period. Discount rate assumptions are based on an assessment of the risk inherent in the future cash flows of the respective reporting units. The variables within the discount rate, many of which are outside of the Company's control, provide the best estimate of all assumptions applied within the discounted cash flow model. There can be no assurance that operations will achieve the future cash flows reflected in the projections. In determining the fair value under the market approaches, the analysis includes a control premium, which was based on observable market data and a review of selected transactions of companies that operate in the Company's sector. While the Company believes that all assumptions utilized in the testing were appropriate, they may not reflect actual outcomes that could occur. Specific factors that could negatively impact the assumptions used include changes to the discount and growth rates and a change in the equity and enterprise premiums being realized in the market.

Organization and Summary of Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2020

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The accompanying condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for fair presentation of the Company's financial position and results of operations have been included. The Company’s fiscal year ends on December 31 and interim results are not necessarily indicative of results for a full year or any other interim period. The information contained in these condensed consolidated financial statements should be read in conjunction with the Company’s consolidated financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2019 (the "2019 Annual Report on Form 10-K").

Principles of Consolidation

The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, as well as interests in partnerships and limited liability companies controlled by the Company through its ownership of a majority voting interest or other rights granted to the Company by contract to manage and control the affiliate's business. All significant intercompany balances and transactions are eliminated in consolidation.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and footnotes. Examples include, but are not limited to, estimates of accounts receivable allowances, professional and general liabilities and the estimate of deferred tax assets or liabilities. Actual results could differ from those estimates.

Variable Interest Entities

Variable Interest EntitiesThe condensed consolidated financial statements include the accounts of variable interest entities ("VIE") in which the Company is the primary beneficiary under the provisions of the Financial Accounting Standards Board's ("FASB") Accounting Standards Codification 810, "Consolidation". The Company has the power to direct the activities that most significantly impact a VIEs economic performance. Additionally, the Company would absorb the majority of the expected losses from any of these entities should such expected losses occur.

Fair Value of Financial Instruments

The fair value of a financial instrument is the amount at which the instrument could be exchanged in an orderly transaction between market participants to sell the asset or transfer the liability. The Company uses fair value measurements based on inputs classified into the following hierarchy:

•Level 1: Unadjusted quoted prices in active markets for identical assets or liabilities.

•Level 2: Inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly. These may include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active.

•Level 3: Unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions, depending on the nature of the item being valued.

The carrying amounts reported in the condensed consolidated balance sheets for cash and cash equivalents, accounts receivable, restricted invested assets and accounts payable approximate their fair values under Level 3 inputs.

The fair values in the table above were based on a Level 2 inputs using quoted prices for identical liabilities in inactive markets. The carrying amounts related to the Company's other long-term debt obligations, including finance lease obligations, approximate their fair values under Level 3 inputs.

The Company has entered into certain interest rate swap agreements (see Note 7. "Derivatives and Hedging Activities"). The fair value of these derivative instruments was $65.3 million and $50.7 million at September 30, 2020 and December 31, 2019, respectively, and was included in other long-term liabilities in the condensed consolidated balance sheets. The fair value of these derivative financial instruments was based on a quoted market price, or a Level 2 input.

Revenues

The Company's revenues generally relate to contracts with patients in which the performance obligations are to provide health care services. The Company recognizes revenues in the period in which our obligations to provide health care services are satisfied and reports the amount that reflects the consideration the Company expects to be entitled to receive. The contractual relationships with patients, in most cases, also involve a third-party payor (e.g., Medicare, Medicaid and private insurance organizations, including plans offered through the health insurance exchanges) and the transaction prices for the services provided are dependent upon the terms provided by or negotiated with the third-party payors. The payment arrangements with third-party payors for the services provided to the related patients typically specify payments at amounts less than the Company's standard charges. The Company continually reviews the contractual estimation process to consider and incorporate updates to laws and regulations and the frequent changes in managed care contractual terms resulting from contract renegotiations and renewals.

Patient service revenues. This revenue is related to charging facility fees in exchange for providing patient care. The fee charged for health care procedures performed in surgical facilities varies depending on the type of service provided, but usually includes all charges for usage of an operating room, a recovery room, special equipment, medical supplies, nursing staff and medications. The fee does not normally include professional fees charged by the patient’s surgeon, anesthesiologist or other attending physician, which are billed directly by such physicians to the patient or third-party payor. However, in several surgical facilities, the Company charges for anesthesia services. Ancillary service revenues include fees for patient visits to the Company's physician practices, pharmacy services and diagnostic tests ordered by physicians.

Patient service revenues are recognized as performance obligations are satisfied. Performance obligations are based on the nature of services provided. Typically, the Company recognizes revenue at a point in time in which services are rendered and the Company has no obligation to provide further patient services. As the Company primarily performs outpatient procedures, performance obligations are generally satisfied same day and revenue is recognized on the date of service.

The Company determines the transaction price based on gross charges for services provided, net of estimated contractual adjustments and discounts from third-party payors. The Company estimates its contractual adjustments and discounts based on contractual agreements, its discount policies and historical experience. Changes in estimated contractual adjustments and discounts are recorded in the period of change.

Other service revenues. Optical service revenues consist of handling charges billed to the members of the Company's optical products purchasing organization. The Company's optical products purchasing organization negotiates volume buying discounts with optical products manufacturers. The buying discounts and any handling charges billed to the members of the buying group represent the revenue recognized for financial reporting purposes. The Company satisfies the performance obligation and recognizes revenue when the orders are shipped to members. The Company bases its estimates for sales returns and discounts on historical experience and has not experienced significant fluctuations between estimated and actual return activity and discounts given.

Other revenues include management and administrative service fees derived from the non-consolidated facilities that the Company accounts for under the equity method, management of surgical facilities in which it does not own an interest, and management services provided to physician practices for which the Company is not required to provide capital or additional assets. These agreements typically require the Company to provide recurring management services over a multi-year period, which are billed and collected on a monthly basis. The fees derived from these management arrangements are based on a predetermined percentage of the revenues of each facility or practice and are recognized in the period in which management services are rendered and billed.

Cash, Cash Equivalents and Restricted Cash

The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. The Company maintains its cash and cash equivalent balances at high credit quality financial institutions.

Cash, cash equivalents and restricted cash reported within the consolidated statement of cash flows includes $0.3 million of restricted investments, which are reflected in other long-term assets in the consolidated balance sheet at both September 30, 2020 and December 31, 2019. These restricted investments represent restricted cash held in accordance with the provisions of a long-term operating lease agreement held as security for performance under the Company's covenants and obligations within the agreement through January 2024.

Accounts Receivable

Accounts receivable from third-party payors are recorded net of estimated implicit price concessions, which are estimated based on the historical trend of the Company's surgical facilities’ cash collections and contractual write-offs, established fee schedules, relationships with payors and procedure statistics. While changes in estimated reimbursement from third-party payors remain a possibility, the Company expects that any such changes would be minimal and, therefore, would not have a material effect on its financial condition or results of operations.

Accounts receivable consists of receivables from federal and state agencies (under the Medicare and Medicaid programs), private insurance organizations, employers and patients. Management recognizes that revenues and receivables from government agencies are significant to the Company's operations, but it does not believe that there is significant credit risk associated with these government agencies. Concentration of credit risk with respect to other payors is limited because of the large number of such payors. As of

September 30, 2020 and December 31, 2019, the Company had a net third-party Medicaid settlements liability of $15.7 million and $5.6 million, respectively, included in other current liabilities in the condensed consolidated balance sheets.

The Company recognizes that final reimbursement of accounts receivable is subject to final approval by each third-party payor. However, because the Company has contracts with its third-party payors and also verifies insurance coverage of the patient before medical services are rendered, the amounts that are pending approval from third-party payors are not considered significant. Amounts are classified outside of self-pay if the Company has an agreement with the third-party payor or has verified a patient’s coverage prior to services rendered. The Company's policy is to collect co-payments and deductibles prior to providing medical services. Patient services of the Company are primarily non-emergency, which allows the surgical facilities to control the procedures for which third-party reimbursement is sought and obtained. The Company does not require collateral from self-pay patients.

The Company's collection policies and procedures are based on the type of payor, size of claim and estimated collection percentage for each patient account. The operating systems used to manage patient accounts provide for an aging schedule in 30-day increments, by payor, physician and patient. The Company analyzes accounts receivable at each of its surgical facilities to ensure the proper collection and aged category. The operating systems generate reports that assist in the collection efforts by prioritizing patient accounts. Collection efforts include direct contact with third-party payors or patients, written correspondence and the use of legal or collection agency assistance, as required.

The receivables related to the Company's optical products purchasing organization are recognized separately from patient accounts receivable, as discussed above, and are included in other current assets in the condensed consolidated balance sheets.

Derivative Instruments and Hedging Activities

The Company records all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain of its risk, even though hedge accounting does not apply or the Company elects not to apply hedge accounting.

The Company made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio.

The Company’s objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company primarily uses interest rate swaps as part of its interest rate risk management strategy. During 2020, such derivatives have been used to hedge the variable cash flows associated with existing variable-rate debt. For derivatives designated and that qualify as cash flow hedges of interest rate risk, the gain or loss on the derivative is recorded in accumulated other comprehensive income ("OCI") and subsequently reclassified into interest expense in the same period(s) during which the hedged transaction affects earnings, as documented at hedge inception in accordance with the Company’s accounting policy election. Amounts reported in accumulated OCI related to derivatives will be reclassified to interest expense as interest payments are made on the Company’s variable-rate debt.

Non-Controlling Interests—Redeemable

Each partnership and limited liability company through which the Company owns and operates its surgical facilities is governed by a partnership or operating agreement, respectively. In certain circumstances, the applicable partnership or operating agreements for the Company's surgical facilities provide that the facilities will purchase all of the physician limited partners’ or physician minority members’, as applicable, ownership if certain adverse regulatory events occur, such as it becoming illegal for the physician(s) to own an interest in a surgical facility, refer patients to a surgical facility or receive cash distributions from a surgical facility. The non-controlling interests—redeemable are reported outside of stockholders' equity in the condensed consolidated balance sheets.

Income Taxes

The Company uses the asset and liability method to account for income taxes. Under this method, deferred income tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. If a carryforward exists, the Company makes a determination as to whether the carryforward will be utilized in the future. A valuation allowance is established for certain carryforwards when their recoverability is deemed to be uncertain. The carrying value of the net deferred tax assets

assumes that the Company will be able to generate sufficient future taxable income in certain tax jurisdictions, based on estimates and assumptions. If our expectations for future operating results on a consolidated basis or at the state jurisdiction level vary from actual results due to changes in health care regulations, general economic conditions, or other factors, we may need to adjust the valuation allowance, for all or a portion of our deferred tax assets. Our income tax expense in future periods will be reduced or increased to the extent of offsetting decreases or increases, respectively, in our valuation allowance in the period when the change in circumstances occurs. These changes could have a significant impact on our future earnings.

The Company and certain of its subsidiaries file a consolidated federal income tax return. The partnerships, limited liability companies, and certain non-consolidated physician practice corporations also file separate income tax returns. The Company's allocable portion of each partnership's and limited liability company's income or loss is included in taxable income of the Company. The remaining income or loss of each partnership and limited liability company is allocated to the other owners.

The Company's effective tax rate was 23.7% for the nine months ended September 30, 2020 compared to 18.5% for the nine months ended September 30, 2019. The higher effective tax rate for the 2020 period was primarily due to (a) discrete tax benefits of approximately $6.9 million attributable to the release of federal and state valuation allowances on the Company’s Internal Revenue Code Section 163(j) interest carryforwards as a result of the increase in deductible interest expense allowed under the CARES Act, and $5.0 million attributable to a portion of the payments under the Settlement Agreement, as defined in Note 10. "Commitments and Contingencies," being classified as "restitution" for income tax purposes; and (b) a discrete tax expense of approximately $5.0 million attributable to the Company's impairment of goodwill. Based upon the application of interim accounting guidance, the tax rate as a percentage of net income after income attributable to non-controlling interests will vary based upon the relative net income from period to period.

Recent Accounting Pronouncements

In March 2020, the FASB issued Accounting Standards Update (“ASU”) 2020-04 Reference Rate Reform (Topic 848). ASU 2020-04 contains practical expedients for reference rate reform related activities that impact debt, leases, derivatives and other contracts. The guidance in ASU 2020-04 is optional and may be elected over time as reference rate reform activities occur. During the nine months ended September 30, 2020, the Company elected to apply the hedge accounting expedients related to probability and the assessments of effectiveness for future London Interbank Offered Rate ("LIBOR") indexed cash flows to assume that the index upon which future hedged transactions will be based matches the index on the corresponding derivatives. Application of these expedients preserves the presentation of derivatives consistent with past presentation. The Company continues to evaluate the impact of the guidance and may apply other elections as applicable as additional changes in the market occur.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses, which introduced a new model for recognizing credit losses on financial instruments based on an estimate of the current expected credit losses. The new current expected credit losses (“CECL”) model generally calls for the immediate recognition of all expected credit losses and applies to financial instruments and other assets, which is primarily applicable to accounts receivable for the Company. This ASU was effective for the Company on January 1, 2020. The adoption of this ASU did not have a material impact on its consolidated financial position and results of operations.

Goodwill

Goodwill represents the fair value of the consideration provided in an acquisition over the fair value of net assets acquired and is not amortized. Additions to goodwill include amounts resulting from new business combinations and incremental ownership purchases in the Company's subsidiaries.

The Company tests its goodwill and indefinite-lived intangible assets for impairment at least annually, as of October 1, or more frequently if certain indicators arise. The Company tests for goodwill impairment at the reporting unit level, which is defined as one level below an operating segment. A detailed evaluation of potential impairment indicators was performed as of September 30, 2020, which specifically considered the volatility observed in the prices of the Company’s outstanding debt securities and common stock, as well as the decline in surgical case volumes following the emergence of the COVID-19 pandemic, all of which improved throughout the second and third quarters as states began to re-open and allow for non-emergent procedures. As of September 30, 2020, the Company has identified three reporting units, which include the following: 1) Surgical Facilities, 2) Ancillary Services, and 3) Alliance, which is a component of the Optical Services operating segment. On the basis of available evidence as of September 30, 2020, no indicators of impairment were identified for the Company's Surgical Facilities reporting unit. The Company did identify indicators of impairment related to its Ancillary Services and Alliance reporting units, including the impacts of the COVID-19 pandemic and the closure of its diagnostic laboratory (as discussed in Note 2. "Acquisitions and Disposals"). Based on the impairment indicators for these reporting units, the Company performed an impairment analysis as of September 30, 2020.

The Company compares the carrying value of the net assets of the reporting unit to the estimated fair value of the reporting unit. To determine the fair value of the reporting units, the Company obtained valuations at the reporting unit level prepared by third-party valuation specialists which utilized a combination of the income and market approaches. The discounted cash flow model is projected based on a year-by-year assessment that considers historical results, estimated market conditions, internal projections, and relevant publicly available statistics. Determining fair value requires the exercise of significant judgment, including assumptions about appropriate discount rates, perpetual growth rates and the amount and timing of expected future cash flows. The significant judgments are typically based upon Level 3 inputs, generally defined as unobservable inputs representing the Company's own assumptions. The cash flows employed in the discounted cash flow analysis are based on the Company's most recent budgets and business plans aligned with provided guidance and, when applicable, various growth rates are assumed for years beyond the current business plan period. Discount rate assumptions are based on an assessment of the risk inherent in the future cash flows of the respective reporting units. The variables within the discount rate, many of which are outside of the Company's control, provide the best estimate of all assumptions applied within the discounted cash flow model. There can be no assurance that operations will achieve the future cash flows reflected in the projections. In determining the fair value under the market approaches, the analysis includes a control premium, which was based on observable market data and a review of selected transactions of companies that operate in the Company's sector. While the Company believes that all assumptions utilized in the testing were appropriate, they may not reflect actual outcomes that could occur. Specific factors that could negatively impact the assumptions used include changes to the discount and growth rates and a change in the equity and enterprise premiums being realized in the market.