Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2020
Accounting Policies [Abstract]
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 reported amounts of assets and liabilities, including disclosure of contingencies, at the date of the financial statements and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Recent and Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements Financial Instruments On January 1, 2020, the Company adopted Accounting Standards Update (“ASU”) 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments (Topic 326), which replaced the incurred loss approach for recognizing credit losses on financial instruments with an expected loss approach. The expected loss approach is subject to management judgments using assessments of incurred credit losses, assessments of current conditions, and forecasts using reasonable and supportable assumptions. The standard was required to be applied using the modified retrospective approach with a cumulative-effect adjustment to retained earnings, if any, upon adoption. The Company’s primary financial instrument subject to the standard is its accounts receivable derived from contracts with patients. Historically, the Company has experienced infrequent, immaterial credit losses related to its accounts receivable and, based on its experience, believes the risk of material defaults is low. The Company experienced credit losses of $1.1 million for the year ended December 31, 2017, credit loss recoveries of $0.1 million for the year ended December 31, 2018, and credit losses of $3.0 million for the year ended December 31, 2019. The Company’s historical credit losses have been infrequent and immaterial largely because the Company’s accounts receivable are typically paid for by highly-solvent, creditworthy payors such as Medicare, other governmental programs, and highly-regulated commercial insurers, on behalf of the patient. The Company believes it has moderate credit risk related to defaults on self-pay amounts in accounts receivable; however, these amounts represented less than 1.0% of the Company’s accounts receivable at January 1, 2020. In estimating the Company’s expected credit losses under Topic 326, the Company considers its incurred loss experience and adjusts for known and expected events and other circumstances, identified using periodic assessments implemented by the Company, which management believes are relevant in assessing the collectability of its accounts receivable. Because of the infrequent and insignificant nature of the Company’s historical credit losses, forecasts of expected credit losses are generally unnecessary. Expected credit losses are recognized by the Company through an allowance for credit losses and related credit loss expense. As of January 1, 2020, the Company completed its expected credit loss assessment for its financial instruments subject to Topic 326. The Company’s estimate of expected credit losses as of January 1, 2020, resulted in no adjustments to the allowance for credit losses and no cumulative-effect adjustment to retained earnings on the adoption date of the standard.
Credit Risk Concentrations	Credit Risk Concentrations Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash balances and accounts receivables. The Company’s excess cash is held with large financial institutions. The Company grants unsecured credit to its patients, most of whom reside in the service area of the Company’s facilities and are insured under third-party payor agreements. The Company’s general policy is to verify insurance coverage prior to the date of admission for patients admitted to its critical illness recovery hospitals and rehabilitation hospitals. Within the Company’s outpatient rehabilitation clinics, insurance coverage is verified prior to the patient’s visit. Within the Company’s Concentra centers, insurance coverage is verified or an authorization is received from the patient’s employer prior to the patient’s visit. Because of the diversity in the Company’s non-governmental third-party payor base, as well as their geographic dispersion, patient accounts receivable which are due from the Medicare program represent the Company’s only significant concentration of credit risk.
Redeemable Non-Controlling Interests	Redeemable Non-Controlling Interests The ownership interests held by outside parties in subsidiaries, limited liability companies, and limited partnerships controlled by the Company are classified as non-controlling interests. Some of the Company’s non-controlling ownership interests consist of outside parties that have certain redemption rights that, if exercised, require the Company to purchase the parties’ ownership interests. These interests are classified and reported as redeemable non-controlling interests and have been adjusted to their approximate redemption values.
Variable Interest Entities	Variable Interest Entities Concentra does not own many of its medical practices, as certain states prohibit the “corporate practice of medicine,” which restricts business corporations from practicing medicine through the direct employment of physicians or from exercising control over medical decisions by physicians. In these states, Concentra typically enters into long-term management agreements with professional corporations or associations that are owned by licensed physicians, which, in turn, employ or contract with physicians who provide professional medical services in Concentra’s occupational health centers. The management agreements have terms that provide for Concentra to conduct, supervise, and manage the day-to-day non-medical operations of the occupational health centers and provide all management and administrative services. Concentra receives a management fee for these services, which is based, in part, on the performance of the professional corporation or association. Additionally, the outstanding voting equity interests of the professional corporations or associations are typically owned by licensed physicians appointed at Concentra’s discretion. Concentra has the ability to direct the transfer of ownership of the professional corporation or association to a new licensed physician at any time.

Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2020

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, including disclosure of contingencies, at the date of the financial statements and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Recent and Recently Adopted Accounting Pronouncements

Recently Adopted Accounting Pronouncements

Financial Instruments

On January 1, 2020, the Company adopted Accounting Standards Update (“ASU”) 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments (Topic 326), which replaced the incurred loss approach for recognizing credit losses on financial instruments with an expected loss approach. The expected loss approach is subject to management judgments using assessments of incurred credit losses, assessments of current conditions, and forecasts using reasonable and supportable assumptions. The standard was required to be applied using the modified retrospective approach with a cumulative-effect adjustment to retained earnings, if any, upon adoption.

The Company’s primary financial instrument subject to the standard is its accounts receivable derived from contracts with patients. Historically, the Company has experienced infrequent, immaterial credit losses related to its accounts receivable and, based on its experience, believes the risk of material defaults is low. The Company experienced credit losses of $1.1 million for the year ended December 31, 2017, credit loss recoveries of $0.1 million for the year ended December 31, 2018, and credit losses of $3.0 million for the year ended December 31, 2019. The Company’s historical credit losses have been infrequent and immaterial largely because the Company’s accounts receivable are typically paid for by highly-solvent, creditworthy payors such as Medicare, other governmental programs, and highly-regulated commercial insurers, on behalf of the patient. The Company believes it has moderate credit risk related to defaults on self-pay amounts in accounts receivable; however, these amounts represented less than 1.0% of the Company’s accounts receivable at January 1, 2020.

In estimating the Company’s expected credit losses under Topic 326, the Company considers its incurred loss experience and adjusts for known and expected events and other circumstances, identified using periodic assessments implemented by the Company, which management believes are relevant in assessing the collectability of its accounts receivable. Because of the infrequent and insignificant nature of the Company’s historical credit losses, forecasts of expected credit losses are generally unnecessary. Expected credit losses are recognized by the Company through an allowance for credit losses and related credit loss expense.

As of January 1, 2020, the Company completed its expected credit loss assessment for its financial instruments subject to Topic 326. The Company’s estimate of expected credit losses as of January 1, 2020, resulted in no adjustments to the allowance for credit losses and no cumulative-effect adjustment to retained earnings on the adoption date of the standard.

Credit Risk Concentrations

Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash balances and accounts receivables. The Company’s excess cash is held with large financial institutions. The Company grants unsecured credit to its patients, most of whom reside in the service area of the Company’s facilities and are insured under third-party payor agreements. The Company’s general policy is to verify insurance coverage prior to the date of admission for patients admitted to its critical illness recovery hospitals and rehabilitation hospitals. Within the Company’s outpatient rehabilitation clinics, insurance coverage is verified prior to the patient’s visit. Within the Company’s Concentra centers, insurance coverage is verified or an authorization is received from the patient’s employer prior to the patient’s visit.

Because of the diversity in the Company’s non-governmental third-party payor base, as well as their geographic dispersion, patient accounts receivable which are due from the Medicare program represent the Company’s only significant concentration of credit risk.

Redeemable Non-Controlling Interests

The ownership interests held by outside parties in subsidiaries, limited liability companies, and limited partnerships controlled by the Company are classified as non-controlling interests. Some of the Company’s non-controlling ownership interests consist of outside parties that have certain redemption rights that, if exercised, require the Company to purchase the parties’ ownership interests. These interests are classified and reported as redeemable non-controlling interests and have been adjusted to their approximate redemption values.

Variable Interest Entities

Concentra does not own many of its medical practices, as certain states prohibit the “corporate practice of medicine,” which restricts business corporations from practicing medicine through the direct employment of physicians or from exercising control over medical decisions by physicians. In these states, Concentra typically enters into long-term management agreements with professional corporations or associations that are owned by licensed physicians, which, in turn, employ or contract with physicians who provide professional medical services in Concentra’s occupational health centers.

The management agreements have terms that provide for Concentra to conduct, supervise, and manage the day-to-day non-medical operations of the occupational health centers and provide all management and administrative services. Concentra receives a management fee for these services, which is based, in part, on the performance of the professional corporation or association. Additionally, the outstanding voting equity interests of the professional corporations or associations are typically owned by licensed physicians appointed at Concentra’s discretion. Concentra has the ability to direct the transfer of ownership of the professional corporation or association to a new licensed physician at any time.