Select Medical (SEM) 10-Q 2 Nov 23 2023 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2023	Oct. 31, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	001-34465
Entity Registrant Name	SELECT MEDICAL HOLDINGS CORP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-1764048
Entity Address, Address Line One	4714 Gettysburg Road
Entity Address, Address Line Two	P.O. Box 2034
Entity Address, City or Town	Mechanicsburg
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	17055
City Area Code	717
Local Phone Number	972-1100
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	SEM
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		128,213,538
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001320414

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 77,440	$ 97,906
Accounts receivable	944,219	941,312
Prepaid income taxes	22,716	31,868
Current portion of interest rate cap contract	85,896	74,857
Other current assets	145,816	125,370
Total Current Assets	1,276,087	1,271,313
Operating lease right-of-use assets	1,180,907	1,169,740
Property and equipment, net	1,006,842	1,001,440
Goodwill	3,504,654	3,484,200
Identifiable intangible assets, net	336,639	351,662
Interest rate cap contract, net of current portion	0	45,200
Other assets	378,879	341,738
Total Assets	7,684,008	7,665,293
Current Liabilities:
Overdrafts	29,994	31,961
Current operating lease liabilities	242,594	236,784
Current portion of long-term debt and notes payable	35,085	44,351
Accounts payable	183,086	186,729
Accrued payroll	210,088	209,789
Accrued vacation	154,655	150,695
Accrued interest	12,044	29,837
Accrued other	297,931	264,525
Income taxes payable	579	480
Total Current Liabilities	1,166,056	1,155,151
Non-current operating lease liabilities	1,019,185	1,008,394
Long-term debt, net of current portion	3,695,244	3,835,211
Non-current deferred tax liability	146,919	169,793
Other non-current liabilities	106,216	106,137
Total Liabilities	6,133,620	6,274,686
Commitments and contingencies (Note 13)
Redeemable non-controlling interests	26,999	34,043
Stockholders’ Equity:
Common stock, $0.001 par value, 700,000,000 shares authorized, 127,173,871 and 128,287,211 shares issued and outstanding at 2022 and 2023, respectively	128	127
Capital in excess of par	482,290	452,183
Retained earnings	722,665	581,010
Accumulated other comprehensive income	62,727	88,602
Total Stockholders’ Equity	1,267,810	1,121,922
Non-controlling interests	255,579	234,642
Total Equity	1,523,389	1,356,564
Total Liabilities and Equity	$ 7,684,008	$ 7,665,293

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (unaudited) (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	700,000,000	700,000,000
Common stock, shares issued (in shares)	128,287,211	127,173,871
Common stock, shares outstanding (in shares)	128,287,211	127,173,871

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Revenue	$ 1,665,694	$ 1,567,794	$ 5,005,202	$ 4,752,082
Costs and expenses:
Cost of services, exclusive of depreciation and amortization	1,442,509	1,393,817	4,284,931	4,191,377
General and administrative	41,316	39,491	126,103	114,272
Depreciation and amortization	52,394	51,459	154,758	153,579
Total costs and expenses	1,536,219	1,484,767	4,565,792	4,459,228
Other operating income	485	8,440	1,211	23,565
Income from operations	129,960	91,467	440,621	316,419
Other income and expense:
Loss on early retirement of debt	(14,692)	0	(14,692)	0
Equity in earnings of unconsolidated subsidiaries	11,561	8,084	30,618	19,648
Interest expense	(50,271)	(45,204)	(147,839)	(121,770)
Income before income taxes	76,558	54,347	308,708	214,297
Income tax expense	15,742	16,221	70,775	53,983
Net income	60,816	38,126	237,933	160,314
Less: Net income attributable to non-controlling interests	12,636	10,960	40,711	28,824
Net income attributable to Select Medical Holdings Corporation	$ 48,180	$ 27,166	$ 197,222	$ 131,490
Earnings per common share (Note 12):
Basic (in dollars per share)	$ 0.38	$ 0.21	$ 1.55	$ 1.01
Diluted (in dollars per share)	$ 0.38	$ 0.21	$ 1.55	$ 1.01

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 60,816	$ 38,126	$ 237,933	$ 160,314
Other comprehensive income (loss), net of tax:
Gain on interest rate cap contract	3,895	31,079	18,726	82,726
Reclassification adjustment for gains included in net income	(16,215)	(4,485)	(44,601)	(4,452)
Net change, net of tax benefit (expense) of $(8,865), $3,998, $(26,092), and $8,397	(12,320)	26,594	(25,875)	78,274
Comprehensive income	48,496	64,720	212,058	238,588
Less: Comprehensive income attributable to non-controlling interests	12,636	10,960	40,711	28,824
Comprehensive income attributable to Select Medical Holdings Corporation	$ 35,860	$ 53,760	$ 171,347	$ 209,764

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
Tax benefit (expense) on components of other comprehensive income	$ 3,998	$ (8,865)	$ 8,397	$ (26,092)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Changes in Equity and Income (unaudited) - USD ($) $ in Thousands	Total	Total Stockholders’ Equity	Common Stock	Capital in Excess of Par	Retained Earnings	Accumulated Other Comprehensive Income	Non-controlling Interests
Beginning balance (in shares) at Dec. 31, 2021			133,884,000
Beginning balance at Dec. 31, 2021	$ 1,325,902	$ 1,109,981	$ 134	$ 504,314	$ 593,251	$ 12,282	$ 215,921
Increase (Decrease) in Stockholders' Equity
Net income attributable to Select Medical Holdings Corporation	49,117	49,117			49,117
Net income attributable to non-controlling interests	4,891	0					4,891
Cash dividends declared for common stockholders ($0.125 per share)	(16,691)	(16,691)			(16,691)
Issuance of restricted stock (in shares)			13,000
Issuance of restricted stock	0	0	$ 0	0
Vesting of restricted stock	8,288	8,288		8,288
Repurchase of common shares (in shares)			(2,128,000)
Repurchase of common shares	(51,676)	(51,676)	$ (2)	(23,459)	(28,215)
Issuance of non-controlling interests	5,229	651		651			4,578
Non-controlling interests acquired in business combination, measurement period adjustment	12,463	0					12,463
Distributions to and purchases of non-controlling interests	(9,097)	0					(9,097)
Redemption value adjustment on non-controlling interests	(1,381)	(1,381)			(1,381)
Other comprehensive income (loss)	39,853	39,853				39,853
Other	(2)	(2)			(2)
Ending balance (in shares) at Mar. 31, 2022			131,769,000
Ending balance at Mar. 31, 2022	1,366,896	1,138,140	$ 132	489,794	596,079	52,135	228,756
Beginning balance (in shares) at Dec. 31, 2021			133,884,000
Beginning balance at Dec. 31, 2021	1,325,902	1,109,981	$ 134	504,314	593,251	12,282	215,921
Increase (Decrease) in Stockholders' Equity
Net income attributable to Select Medical Holdings Corporation	131,490
Ending balance (in shares) at Sep. 30, 2022			127,144,000
Ending balance at Sep. 30, 2022	1,334,519	1,105,595	$ 127	444,843	570,069	90,556	228,924
Beginning balance (in shares) at Mar. 31, 2022			131,769,000
Beginning balance at Mar. 31, 2022	1,366,896	1,138,140	$ 132	489,794	596,079	52,135	228,756
Increase (Decrease) in Stockholders' Equity
Net income attributable to Select Medical Holdings Corporation	55,207	55,207			55,207
Net income attributable to non-controlling interests	9,155	0					9,155
Cash dividends declared for common stockholders ($0.125 per share)	(16,108)	(16,108)			(16,108)
Issuance of restricted stock (in shares)			211,000
Issuance of restricted stock	0	0	$ 0	0
Forfeitures of unvested restricted stock (in shares)			(6,000)
Forfeitures of unvested restricted stock	3	3	$ 0	0	3
Vesting of restricted stock	8,406	8,406		8,406
Repurchase of common shares (in shares)			(5,483,000)
Repurchase of common shares	(126,947)	(126,947)	$ (6)	(56,965)	(69,976)
Issuance of non-controlling interests	1,725	0					1,725
Distributions to and purchases of non-controlling interests	(6,814)	534		534			(7,348)
Redemption value adjustment on non-controlling interests	355	355			355
Other comprehensive income (loss)	11,827	11,827				11,827
Other	(4)	(4)			(4)
Ending balance (in shares) at Jun. 30, 2022			126,491,000
Ending balance at Jun. 30, 2022	1,303,701	1,071,413	$ 126	441,769	565,556	63,962	232,288
Increase (Decrease) in Stockholders' Equity
Net income attributable to Select Medical Holdings Corporation	27,166	27,166			27,166
Net income attributable to non-controlling interests	8,720	0					8,720
Cash dividends declared for common stockholders ($0.125 per share)	(15,893)	(15,893)			(15,893)
Issuance of restricted stock (in shares)			1,228,000
Issuance of restricted stock	0	0	$ 1	(1)
Forfeitures of unvested restricted stock (in shares)			(6,000)
Forfeitures of unvested restricted stock	3	3	$ 0	0	3
Vesting of restricted stock	9,649	9,649		9,649
Repurchase of common shares (in shares)			(569,000)
Repurchase of common shares	(14,991)	(14,991)	$ 0	(6,574)	(8,417)
Issuance of non-controlling interests	142	0					142
Distributions to and purchases of non-controlling interests	(14,676)	(2,450)			(2,450)		(12,226)
Redemption value adjustment on non-controlling interests	4,108	4,108			4,108
Other comprehensive income (loss)	26,594	26,594				26,594
Other	(4)	(4)			(4)
Ending balance (in shares) at Sep. 30, 2022			127,144,000
Ending balance at Sep. 30, 2022	$ 1,334,519	1,105,595	$ 127	444,843	570,069	90,556	228,924
Beginning balance (in shares) at Dec. 31, 2022	127,173,871		127,173,000
Beginning balance at Dec. 31, 2022	$ 1,356,564	1,121,922	$ 127	452,183	581,010	88,602	234,642
Increase (Decrease) in Stockholders' Equity
Net income attributable to Select Medical Holdings Corporation	70,805	70,805			70,805
Net income attributable to non-controlling interests	12,811	0					12,811
Cash dividends declared for common stockholders ($0.125 per share)	(15,897)	(15,897)			(15,897)
Issuance of restricted stock (in shares)			3,000
Issuance of restricted stock	0	0	$ 0	0
Vesting of restricted stock	10,003	10,003		10,003
Issuance of non-controlling interests	2,731	0					2,731
Non-controlling interests acquired in business combination, measurement period adjustment	3,877	0					3,877
Distributions to and purchases of non-controlling interests	(6,069)	0					(6,069)
Redemption value adjustment on non-controlling interests	(436)	(436)			(436)
Other comprehensive income (loss)	(15,948)	(15,948)				(15,948)
Other	0	0		(1)	1
Ending balance (in shares) at Mar. 31, 2023			127,176,000
Ending balance at Mar. 31, 2023	$ 1,418,441	1,170,449	$ 127	462,185	635,483	72,654	247,992
Beginning balance (in shares) at Dec. 31, 2022	127,173,871		127,173,000
Beginning balance at Dec. 31, 2022	$ 1,356,564	1,121,922	$ 127	452,183	581,010	88,602	234,642
Increase (Decrease) in Stockholders' Equity
Net income attributable to Select Medical Holdings Corporation	$ 197,222
Ending balance (in shares) at Sep. 30, 2023	128,287,211		128,287,000
Ending balance at Sep. 30, 2023	$ 1,523,389	1,267,810	$ 128	482,290	722,665	62,727	255,579
Beginning balance (in shares) at Mar. 31, 2023			127,176,000
Beginning balance at Mar. 31, 2023	1,418,441	1,170,449	$ 127	462,185	635,483	72,654	247,992
Increase (Decrease) in Stockholders' Equity
Net income attributable to Select Medical Holdings Corporation	78,237	78,237			78,237
Net income attributable to non-controlling interests	11,539	0					11,539
Cash dividends declared for common stockholders ($0.125 per share)	(15,924)	(15,924)			(15,924)
Issuance of restricted stock (in shares)			261,000
Issuance of restricted stock	0	0	$ 0	0
Vesting of restricted stock	10,326	10,326		10,326
Repurchase of common shares (in shares)			(49,000)
Repurchase of common shares	(1,506)	(1,506)	$ 0	(634)	(872)
Issuance of non-controlling interests	12,081	1,870		1,870			10,211
Distributions to and purchases of non-controlling interests	(14,006)	195		195			(14,201)
Redemption value adjustment on non-controlling interests	(2)	(2)			(2)
Other comprehensive income (loss)	2,393	2,393				2,393
Ending balance (in shares) at Jun. 30, 2023			127,388,000
Ending balance at Jun. 30, 2023	1,501,579	1,246,038	$ 127	473,942	696,922	75,047	255,541
Increase (Decrease) in Stockholders' Equity
Net income attributable to Select Medical Holdings Corporation	48,180	48,180			48,180
Net income attributable to non-controlling interests	10,316	0					10,316
Cash dividends declared for common stockholders ($0.125 per share)	(16,035)	(16,035)			(16,035)
Issuance of restricted stock (in shares)			1,217,000
Issuance of restricted stock	0	0	$ 1	(1)
Vesting of restricted stock	11,483	11,483		11,483
Repurchase of common shares (in shares)			(318,000)
Repurchase of common shares	(9,544)	(9,544)	$ 0	(3,866)	(5,678)
Issuance of non-controlling interests	5,651	0					5,651
Non-controlling interests acquired in business combination, measurement period adjustment	5,130	0					5,130
Distributions to and purchases of non-controlling interests	(22,999)	(1,940)		732	(2,672)		(21,059)
Redemption value adjustment on non-controlling interests	1,912	1,912			1,912
Other comprehensive income (loss)	(12,320)	(12,320)				(12,320)
Other	$ 36	36			36
Ending balance (in shares) at Sep. 30, 2023	128,287,211		128,287,000
Ending balance at Sep. 30, 2023	$ 1,523,389	$ 1,267,810	$ 128	$ 482,290	$ 722,665	$ 62,727	$ 255,579

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Changes in Equity and Income (unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022
Statement of Stockholders' Equity [Abstract]
Cash dividend declared (in dollars per share)	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating activities
Net income	$ 237,933	$ 160,314
Adjustments to reconcile net income to net cash provided by operating activities:
Distributions from unconsolidated subsidiaries	9,896	16,892
Depreciation and amortization	154,758	153,579
Provision for expected credit losses	1,101	(41)
Equity in earnings of unconsolidated subsidiaries	(30,618)	(19,648)
Loss on extinguishment of debt	175	0
Gain on sale or disposal of assets	(7)	(1,593)
Stock compensation expense	31,991	27,956
Amortization of debt discount, premium and issuance costs	1,899	1,696
Deferred income taxes	(17,049)	(7,080)
Changes in operating assets and liabilities, net of effects of business combinations:
Accounts receivable	(3,014)	(19,686)
Other current assets	(17,276)	2,923
Other assets	7,028	9,650
Accounts payable	4,788	(22,185)
Accrued expenses	21,011	52,352
Government advances	0	(82,848)
Net cash provided by operating activities	402,616	272,281
Investing activities
Business combinations, net of cash acquired	(20,482)	(22,027)
Purchases of property, equipment, and other assets	(168,597)	(135,119)
Investment in businesses	(9,874)	(17,323)
Proceeds from sale of assets	60	5,364
Net cash used in investing activities	(198,893)	(169,105)
Financing activities
Borrowings on revolving facilities	635,000	845,000
Payments on revolving facilities	(740,000)	(625,000)
Proceeds from term loans	2,092,232	0
Payments on term loans	(2,108,694)	0
Borrowings of other debt	30,849	20,866
Principal payments on other debt	(38,298)	(25,165)
Dividends paid to common stockholders	(47,856)	(48,692)
Repurchase of common stock	(11,050)	(193,614)
Decrease in overdrafts	(1,967)	(9,091)
Proceeds from issuance of non-controlling interests	20,463	7,096
Distributions to and purchases of non-controlling interests	(54,868)	(40,663)
Net cash used in financing activities	(224,189)	(69,263)
Net increase (decrease) in cash and cash equivalents	(20,466)	33,913
Cash and cash equivalents at beginning of period	97,906	74,310
Cash and cash equivalents at end of period	77,440	108,223
Supplemental information
Cash paid for interest, excluding amounts received of $6,232 and $60,353 under the interest rate cap contract	221,697	143,455
Cash paid for taxes	$ 78,502	$ 24,844

Condensed Consolidated Statem_7

Condensed Consolidated Statements of Cash Flows (unaudited) (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Statement of Cash Flows [Abstract]
Interest received under interest rate cash flow hedge	$ 60,353	$ 6,232

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The unaudited condensed consolidated financial statements of Select Medical Holdings Corporation (“Holdings”) include the accounts of its wholly owned subsidiary, Select Medical Corporation (“Select”). Holdings conducts substantially all of its business through Select and its subsidiaries. Holdings, Select, and Select’s subsidiaries are collectively referred to as the “Company.” The unaudited condensed consolidated financial statements of the Company as of September 30, 2023, and for the three and nine month periods ended September 30, 2022 and 2023, have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim reporting and the accounting principles generally accepted in the United States of America (“GAAP”). Accordingly, certain information and disclosures required by GAAP, which are normally included in the notes to the consolidated financial statements, have been condensed or omitted pursuant to those rules and regulations, although the Company believes the disclosure is adequate to make the information presented not misleading. In the opinion of management, such information contains all adjustments, which are normal and recurring in nature, necessary for a fair statement of the financial position, results of operations and cash flow for such periods. All significant intercompany transactions and balances have been eliminated. The results of operations for the three and nine months ended September 30, 2023, are not necessarily indicative of the results to be expected for the full fiscal year ending December 31, 2023. These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto for the year ended December 31, 2022, contained in the Company’s Annual Report on Form 10-K filed with the SEC on February 23, 2023.

Accounting Policies

Accounting Policies	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Accounting Policies	Accounting Policies Recent Accounting Guidance Not Yet Adopted In March 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-01, Leases (Topic 842): Common Control Arrangements , which requires companies to amortize leasehold improvements associated with related party leases under common control over the useful life of the leasehold improvement to the common control group. The ASU is effective for annual reporting periods beginning on or after December 15, 2023; however, early adoption is permitted. The ASU can either be applied prospectively or retrospectively. The Company is currently evaluating this ASU, but does not expect it to have a material impact on its consolidated financial statements upon adoption. The Company plans to adopt the ASU using the prospective method as of January 1, 2024. 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, liabilities, revenues, and expenses. Actual results could differ from those estimates.

Credit Risk Concentrations

Credit Risk Concentrations	9 Months Ended
	Sep. 30, 2023
Credit Loss [Abstract]
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 receivable. 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. Because of the diversity in the Company’s non-governmental third-party payor base, as well as their geographic dispersion, accounts receivable due from the Medicare program represent the Company’s only significant concentration of credit risk. Approximately 19% and 15% of the Company’s accounts receivable is due from Medicare at both December 31, 2022, and September 30, 2023, respectively.

Redeemable Non-Controlling Inte

Redeemable Non-Controlling Interests	9 Months Ended
	Sep. 30, 2023
Noncontrolling Interest [Abstract]
Redeemable Non-Controlling Interests	Redeemable Non-Controlling Interests The ownership interests held by outside parties in subsidiaries, which include 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, after the attribution of net income or loss. The changes in redeemable non-controlling interests are as follows: Nine Months Ended September 30, 2022 2023 (in thousands) Balance as of January 1 $ 39,033 $ 34,043 Net income attributable to redeemable non-controlling interests 1,918 1,641 Distributions to redeemable non-controlling interests (1,198) (1,900) Redemption value adjustment on redeemable non-controlling interests 1,381 436 Other 536 179 Balance as of March 31 $ 41,670 $ 34,399 Net income attributable to redeemable non-controlling interests 1,900 2,084 Distributions to and purchases of redeemable non-controlling interests (1,553) (2,110) Redemption value adjustment on redeemable non-controlling interests (355) 2 Other 535 — Balance as of June 30 $ 42,197 $ 34,375 Net income attributable to redeemable non-controlling interests 2,240 2,320 Distributions to and purchases of redeemable non-controlling interests (7,325) (7,784) Redemption value adjustment on redeemable non-controlling interests (4,108) (1,912) Other 536 — Balance as of September 30 $ 33,540 $ 26,999

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	Variable Interest Entities Certain states prohibit the “corporate practice of medicine,” which restricts the Company from owning medical practices which directly employ physicians or therapists and from exercising control over medical decisions by physicians and therapists. In these states, the Company enters into long-term management agreements with medical practices that are owned by licensed physicians or therapists, which, in turn, employ or contract with physicians or therapists who provide professional medical services. The management agreements provide for the Company to direct the transfer of ownership of the medical practices. Based on the provisions of the management agreements, the medical practices are variable interest entities for which the Company is the primary beneficiary. As of December 31, 2022, and September 30, 2023, the total assets of the Company’s variable interest entities were $232.1 million and $273.4 million, respectively, and are principally comprised of accounts receivable. As of December 31, 2022, and September 30, 2023, the total liabilities of the Company’s variable interest entities were $78.8 million and $85.8 million, respectively, and are principally comprised of accounts payable and accrued expenses. These variable interest entities have obligations payable for services received under their management agreements with the Company of $158.3 million and $195.1 million as of December 31, 2022, and September 30, 2023, respectively. These intercompany balances are eliminated in consolidation.

Leases

Leases	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Leases	Leases The Company’s total lease cost is as follows: Three Months Ended September 30, 2022 Three Months Ended September 30, 2023 Unrelated Parties Related Parties Total Unrelated Parties Related Parties Total (in thousands) Operating lease cost $ 73,795 $ 1,810 $ 75,605 $ 78,147 $ 1,834 $ 79,981 Finance lease cost: Amortization of right-of-use assets 381 — 381 387 — 387 Interest on lease liabilities 335 — 335 352 — 352 Short-term lease cost 24 — 24 — — — Variable lease cost 14,855 141 14,996 16,562 — 16,562 Sublease income (1,963) — (1,963) (1,633) — (1,633) Total lease cost $ 87,427 $ 1,951 $ 89,378 $ 93,815 $ 1,834 $ 95,649 Nine Months Ended September 30, 2022 Nine Months Ended September 30, 2023 Unrelated Parties Related Parties Total Unrelated Parties Related Parties Total (in thousands) Operating lease cost $ 221,726 $ 5,428 $ 227,154 $ 231,671 $ 5,501 $ 237,172 Finance lease cost: Amortization of right-of-use assets 1,105 — 1,105 1,185 — 1,185 Interest on lease liabilities 1,011 — 1,011 1,059 — 1,059 Short-term lease cost 74 — 74 — — — Variable lease cost 42,917 321 43,238 48,854 84 48,938 Sublease income (5,869) — (5,869) (5,027) — (5,027) Total lease cost $ 260,964 $ 5,749 $ 266,713 $ 277,742 $ 5,585 $ 283,327
Leases	Leases The Company’s total lease cost is as follows: Three Months Ended September 30, 2022 Three Months Ended September 30, 2023 Unrelated Parties Related Parties Total Unrelated Parties Related Parties Total (in thousands) Operating lease cost $ 73,795 $ 1,810 $ 75,605 $ 78,147 $ 1,834 $ 79,981 Finance lease cost: Amortization of right-of-use assets 381 — 381 387 — 387 Interest on lease liabilities 335 — 335 352 — 352 Short-term lease cost 24 — 24 — — — Variable lease cost 14,855 141 14,996 16,562 — 16,562 Sublease income (1,963) — (1,963) (1,633) — (1,633) Total lease cost $ 87,427 $ 1,951 $ 89,378 $ 93,815 $ 1,834 $ 95,649 Nine Months Ended September 30, 2022 Nine Months Ended September 30, 2023 Unrelated Parties Related Parties Total Unrelated Parties Related Parties Total (in thousands) Operating lease cost $ 221,726 $ 5,428 $ 227,154 $ 231,671 $ 5,501 $ 237,172 Finance lease cost: Amortization of right-of-use assets 1,105 — 1,105 1,185 — 1,185 Interest on lease liabilities 1,011 — 1,011 1,059 — 1,059 Short-term lease cost 74 — 74 — — — Variable lease cost 42,917 321 43,238 48,854 84 48,938 Sublease income (5,869) — (5,869) (5,027) — (5,027) Total lease cost $ 260,964 $ 5,749 $ 266,713 $ 277,742 $ 5,585 $ 283,327

Long-Term Debt and Notes Payabl

Long-Term Debt and Notes Payable	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Long-Term Debt and Notes Payable	Long-Term Debt and Notes Payable As of September 30, 2023, the Company’s long-term debt and notes payable are as follows: Principal Unamortized Premium (Discount) Unamortized Carrying Value Fair Value (in thousands) 6.250% senior notes $ 1,225,000 $ 17,046 $ (8,697) $ 1,233,349 $ 1,193,126 Credit facilities: Revolving facility 340,000 — — 340,000 331,500 Term loan 2,097,743 (12,999) (3,487) 2,081,257 2,087,254 Other debt, including finance leases 75,804 — (81) 75,723 75,723 Total debt $ 3,738,547 $ 4,047 $ (12,265) $ 3,730,329 $ 3,687,603 Principal maturities of the Company’s long-term debt and notes payable are approximately as follows: 2023 2024 2025 2026 2027 Thereafter Total (in thousands) 6.250% senior notes $ — $ — $ — $ 1,225,000 $ — $ — $ 1,225,000 Credit facilities: Revolving facility — — — — 340,000 — 340,000 Term loan 5,258 21,030 21,030 21,030 2,029,395 — 2,097,743 Other debt, including finance leases 5,962 50,988 2,527 2,427 1,941 11,959 75,804 Total debt $ 11,220 $ 72,018 $ 23,557 $ 1,248,457 $ 2,371,336 $ 11,959 $ 3,738,547 As of December 31, 2022, the Company’s long-term debt and notes payable are as follows: Principal Unamortized Premium (Discount) Unamortized Carrying Value Fair Value (in thousands) 6.250% senior notes $ 1,225,000 $ 21,555 $ (10,948) $ 1,235,607 $ 1,163,689 Credit facilities: Revolving facility 445,000 — — 445,000 443,331 Term loan 2,103,437 (4,376) (4,771) 2,094,290 2,056,110 Other debt, including finance leases 104,800 — (135) 104,665 104,665 Total debt $ 3,878,237 $ 17,179 $ (15,854) $ 3,879,562 $ 3,767,795 Select Credit Facilities On July 31, 2023, the Company entered into Amendment No. 8 to the Select credit agreement. Amendment No. 8 provides for a new tranche of term loans in an aggregate principal amount of $2,103.0 million to replace the existing term loans and a $710.0 million new revolving credit facility to replace the $650.0 million existing revolving credit facility. The term loans and the extended revolving credit facility will mature on March 6, 2027, with an early springing maturity 90 days prior to the senior notes maturity, triggered if more than $300.0 million of senior notes remain outstanding on May 15, 2026. The term loans have an interest rate of Term SOFR plus 3.00% and the revolving credit facility has an interest rate of Adjusted Term SOFR (which includes a 0.10% credit spread adjustment) plus 2.50%, subject to a leverage-based pricing grid. During the three months ended September 30, 2023, the Company recognized a $14.7 million loss on early retirement of debt as a result of the amendment to the Select credit agreement. On August 31, 2023, the Company entered into Amendment No. 9 to the Select credit agreement. Amendment No. 9 increased the revolving credit facility commitments from $710.0 million to $770.0 million.

Interest Rate Cap

Interest Rate Cap	9 Months Ended
	Sep. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Interest Rate Cap	Interest Rate Cap The Company is subject to market risk exposure arising from changes in interest rates on its term loan. The term loan bears interest at a variable rate that is indexed to a benchmark which changed from LIBOR to SOFR on May 31, 2023. The Company’s objective in using an interest rate derivative is to mitigate its exposure to increases in interest rates. The interest rate cap limits the Company’s exposure to increases in the variable rate index to 1.0% on $2.0 billion of principal outstanding under the term loan, as the interest rate cap provides for payments from the counterparty when interest rates rise above 1.0%. The interest rate cap has a $2.0 billion notional amount and is effective through September 30, 2024. The Company will pay a monthly premium for the interest rate cap over the term of the agreement. The annual premium is equal to 0.0916% of the notional amount, or approximately $1.8 million. The interest rate cap has been designated as a cash flow hedge and is highly effective at offsetting the changes in cash outflows when the variable rate index exceeds 1.0%. Changes in the fair value of the interest rate cap, net of tax, are recognized in other comprehensive income and are reclassified out of accumulated other comprehensive income and into interest expense when the hedged interest obligations affect earnings. The following table outlines the changes in accumulated other comprehensive income (loss), net of tax, during the periods presented: Nine Months Ended September 30, 2022 2023 (in thousands) Balance as of January 1 $ 12,282 $ 88,602 Gain (loss) on interest rate cap cash flow hedge 39,814 (2,696) Amounts reclassified from accumulated other comprehensive income 39 (13,252) Balance as of March 31 $ 52,135 $ 72,654 Gain on interest rate cap cash flow hedge 11,833 17,527 Amounts reclassified from accumulated other comprehensive income (6) (15,134) Balance as of June 30 $ 63,962 $ 75,047 Gain on interest rate cap cash flow hedge 31,079 3,895 Amounts reclassified from accumulated other comprehensive income (4,485) (16,215) Balance as of September 30 $ 90,556 $ 62,727 The effects on net income of amounts reclassified from accumulated other comprehensive income are as follows: Three Months Ended September 30, Nine Months Ended September 30, Statement of Operations 2022 2023 2022 2023 (in thousands) Gains included in interest expense $ 5,980 $ 21,477 $ 5,936 $ 59,074 Income tax expense (1,495) (5,262) (1,484) (14,473) Amounts reclassified from accumulated other comprehensive income $ 4,485 $ 16,215 $ 4,452 $ 44,601 The Company expects that approximately $83.0 million of estimated pre-tax gains will be reclassified from accumulated other comprehensive income into interest expense within the next twelve months.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments Financial instruments which are measured at fair value, or for which a fair value is disclosed, are classified in the fair value hierarchy, as outlined below, on the basis of the observability of the inputs used in the fair value measurement: • Level 1 – inputs are based upon quoted prices for identical instruments in active markets. • Level 2 – inputs are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant inputs are observable in the market or can be corroborated by observable market data. • Level 3 – inputs are generally unobservable and typically reflect management’s estimates of assumptions that market participants would use in pricing the instrument. The Company’s interest rate cap contract is recorded at its fair value in the condensed consolidated balance sheets on a recurring basis. The fair value of the interest rate cap contract is based upon a model-derived valuation using observable market inputs, such as interest rates and interest rate volatility, and the strike price. Financial Instrument Balance Sheet Classification Level December 31, 2022 September 30, 2023 Asset: (in thousands) Interest rate cap contract, current portion Current portion of interest rate cap contract Level 2 $ 74,857 $ 85,896 Interest rate cap contract, non-current portion Interest rate cap contract, net of current portion Level 2 45,200 — The Company does not measure its indebtedness at fair value in its condensed consolidated balance sheets. The fair value of the credit facilities is based on quoted market prices for this debt in the syndicated loan market. The fair value of the senior notes is based on quoted market prices. The carrying value of the Company’s other debt, as disclosed in Note 7 – Long-Term Debt and Notes Payable, approximates fair value. December 31, 2022 September 30, 2023 Financial Instrument Level Carrying Value Fair Value Carrying Value Fair Value (in thousands) 6.250% senior notes Level 2 $ 1,235,607 $ 1,163,689 $ 1,233,349 $ 1,193,126 Credit facilities: Revolving facility Level 2 445,000 443,331 340,000 331,500 Term loan Level 2 2,094,290 2,056,110 2,081,257 2,087,254

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2023
Segment Reporting [Abstract]
Segment Information	Segment Information The Company’s reportable segments consist of the critical illness recovery hospital segment, rehabilitation hospital segment, outpatient rehabilitation segment, and Concentra segment. Other activities include the Company’s corporate shared services, certain investments, and employee leasing services with non-consolidating subsidiaries. The Company evaluates the performance of its segments based on Adjusted EBITDA. Adjusted EBITDA is defined as earnings excluding interest, income taxes, depreciation and amortization, gain (loss) on early retirement of debt, stock compensation expense, gain (loss) on sale of businesses, and equity in earnings (losses) of unconsolidated subsidiaries. The Company has provided additional information regarding its reportable segments, such as total assets, which contributes to the understanding of the Company and provides useful information to the users of the consolidated financial statements. The following tables summarize selected financial data for the Company’s reportable segments. Three Months Ended September 30, Nine Months Ended September 30, 2022 2023 2022 2023 (in thousands) Revenue: Critical illness recovery hospital $ 524,584 $ 563,628 $ 1,672,247 $ 1,732,645 Rehabilitation hospital 229,387 247,101 678,908 719,419 Outpatient rehabilitation 284,993 291,804 844,191 890,679 Concentra 444,576 473,964 1,309,356 1,397,341 Other 84,254 89,197 247,380 265,118 Total Company $ 1,567,794 $ 1,665,694 $ 4,752,082 $ 5,005,202 Adjusted EBITDA: Critical illness recovery hospital $ 11,013 $ 46,362 $ 66,999 $ 188,631 Rehabilitation hospital 49,772 53,626 141,996 155,531 Outpatient rehabilitation 25,715 26,346 85,912 89,395 Concentra 90,025 98,907 272,101 293,046 Other (1) (23,412) (31,404) (69,054) (99,234) Total Company $ 153,113 $ 193,837 $ 497,954 $ 627,369 Total assets: Critical illness recovery hospital $ 2,368,968 $ 2,454,578 $ 2,368,968 $ 2,454,578 Rehabilitation hospital 1,189,486 1,222,853 1,189,486 1,222,853 Outpatient rehabilitation 1,377,010 1,401,148 1,377,010 1,401,148 Concentra 2,309,392 2,321,671 2,309,392 2,321,671 Other 310,120 283,758 310,120 283,758 Total Company $ 7,554,976 $ 7,684,008 $ 7,554,976 $ 7,684,008 Purchases of property, equipment, and other assets: Critical illness recovery hospital $ 21,534 $ 21,098 $ 60,631 $ 76,119 Rehabilitation hospital 392 4,813 11,487 15,298 Outpatient rehabilitation 10,098 8,855 28,826 29,263 Concentra 9,074 15,456 28,030 45,702 Other 844 (24) 6,145 2,215 Total Company $ 41,942 $ 50,198 $ 135,119 $ 168,597 _______________________________________________________________________________ (1) For the three and nine months ended September 30, 2023, Adjusted EBITDA included other operating income of $0.5 million. For the three and nine months ended September 30, 2022, Adjusted EBITDA included other operating income of $8.1 million and $23.2 million, respectively. The other operating income was principally related to the recognition of payments received under the Provider Relief Fund for health care related expenses and loss of revenue attributable to COVID-19. A reconciliation of Adjusted EBITDA to income before income taxes is as follows: Three Months Ended September 30, 2022 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Adjusted EBITDA $ 11,013 $ 49,772 $ 25,715 $ 90,025 $ (23,412) Depreciation and amortization (16,055) (6,994) (8,157) (17,781) (2,472) Stock compensation expense — — — (535) (9,652) Income (loss) from operations $ (5,042) $ 42,778 $ 17,558 $ 71,709 $ (35,536) $ 91,467 Equity in earnings of unconsolidated subsidiaries 8,084 Interest expense (45,204) Income before income taxes $ 54,347 Three Months Ended September 30, 2023 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Adjusted EBITDA $ 46,362 $ 53,626 $ 26,346 $ 98,907 $ (31,404) Depreciation and amortization (16,402) (7,106) (8,861) (17,959) (2,066) Stock compensation expense — — — — (11,483) Income (loss) from operations $ 29,960 $ 46,520 $ 17,485 $ 80,948 $ (44,953) $ 129,960 Loss on early retirement of debt (14,692) Equity in earnings of unconsolidated subsidiaries 11,561 Interest expense (50,271) Income before income taxes $ 76,558 Nine Months Ended September 30, 2022 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Adjusted EBITDA $ 66,999 $ 141,996 $ 85,912 $ 272,101 $ (69,054) Depreciation and amortization (45,276) (20,971) (24,316) (55,323) (7,693) Stock compensation expense — — — (1,606) (26,350) Income (loss) from operations $ 21,723 $ 121,025 $ 61,596 $ 215,172 $ (103,097) $ 316,419 Equity in earnings of unconsolidated subsidiaries 19,648 Interest expense (121,770) Income before income taxes $ 214,297 Nine Months Ended September 30, 2023 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Adjusted EBITDA $ 188,631 $ 155,531 $ 89,395 $ 293,046 $ (99,234) Depreciation and amortization (46,925) (20,881) (26,097) (54,552) (6,303) Stock compensation expense — — — (178) (31,812) Income (loss) from operations $ 141,706 $ 134,650 $ 63,298 $ 238,316 $ (137,349) $ 440,621 Loss on early retirement of debt (14,692) Equity in earnings of unconsolidated subsidiaries 30,618 Interest expense (147,839) Income before income taxes $ 308,708

Revenue from Contracts with Cus

Revenue from Contracts with Customers	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Revenue from Contracts with Customers The following tables disaggregate the Company’s revenue for the three and nine months ended September 30, 2022 and 2023: Three Months Ended September 30, 2022 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Patient service revenue: Medicare $ 201,558 $ 106,584 $ 45,193 $ 205 $ — $ 353,540 Non-Medicare 320,896 111,509 221,275 443,040 — 1,096,720 Total patient services revenues 522,454 218,093 266,468 443,245 — 1,450,260 Other revenue 2,130 11,294 18,525 1,331 84,254 117,534 Total revenue $ 524,584 $ 229,387 $ 284,993 $ 444,576 $ 84,254 $ 1,567,794 Three Months Ended September 30, 2023 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Patient service revenue: Medicare $ 201,881 $ 115,145 $ 45,286 $ 261 $ — $ 362,573 Non-Medicare 360,847 119,524 228,386 472,171 — 1,180,928 Total patient services revenues 562,728 234,669 273,672 472,432 — 1,543,501 Other revenue 900 12,432 18,132 1,532 89,197 122,193 Total revenue $ 563,628 $ 247,101 $ 291,804 $ 473,964 $ 89,197 $ 1,665,694 Nine Months Ended September 30, 2022 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Patient service revenue: Medicare $ 634,225 $ 314,635 $ 131,530 $ 577 $ — $ 1,080,967 Non-Medicare 1,031,000 331,652 660,345 1,304,865 — 3,327,862 Total patient services revenues 1,665,225 646,287 791,875 1,305,442 — 4,408,829 Other revenue 7,022 32,621 52,316 3,914 247,380 343,253 Total revenue $ 1,672,247 $ 678,908 $ 844,191 $ 1,309,356 $ 247,380 $ 4,752,082 Nine Months Ended September 30, 2023 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Patient service revenue: Medicare $ 639,007 $ 338,650 $ 137,734 $ 754 $ — $ 1,116,145 Non-Medicare 1,090,650 344,885 696,617 1,392,136 — 3,524,288 Total patient services revenues 1,729,657 683,535 834,351 1,392,890 — 4,640,433 Other revenue 2,988 35,884 56,328 4,451 265,118 364,769 Total revenue $ 1,732,645 $ 719,419 $ 890,679 $ 1,397,341 $ 265,118 $ 5,005,202

Earnings per Share

Earnings per Share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Earnings per Share	Earnings per Share The Company’s capital structure includes common stock and unvested restricted stock awards. To compute earnings per share (“EPS”), the Company applies the two-class method because the Company’s unvested restricted stock awards are participating securities which are entitled to participate equally with the Company’s common stock in undistributed earnings. Application of the Company’s two-class method is as follows: (i) Net income attributable to the Company is reduced by the amount of dividends declared and by the contractual amount of dividends that must be paid for the current period for each class of stock. There were no contractual dividends paid for the three and nine months ended September 30, 2022 and 2023. (ii) The remaining undistributed net income of the Company is then equally allocated to its common stock and unvested restricted stock awards, as if all of the earnings for the period had been distributed. The total net income allocated to each security is determined by adding both distributed and undistributed net income for the period. (iii) The net income allocated to each security is then divided by the weighted average number of outstanding shares for the period to determine the EPS for each security considered in the two-class method. The following table sets forth the net income attributable to the Company, its common shares outstanding, and its participating securities outstanding. Basic and Diluted EPS Three Months Ended September 30, Nine Months Ended September 30, 2022 2023 2022 2023 (in thousands) Net income $ 38,126 $ 60,816 $ 160,314 $ 237,933 Less: net income attributable to non-controlling interests 10,960 12,636 28,824 40,711 Net income attributable to the Company 27,166 48,180 131,490 197,222 Less: Distributed and undistributed income attributable to participating securities 992 1,722 4,588 7,155 Distributed and undistributed income attributable to common shares $ 26,174 $ 46,458 $ 126,902 $ 190,067 The following tables set forth the computation of EPS under the two-class method: Three Months Ended September 30, 2022 2023 Net Income Allocation Shares (1) Basic and Diluted EPS Net Income Allocation Shares (1) Basic and Diluted EPS (in thousands, except for per share amounts) Common shares $ 26,174 122,193 $ 0.21 $ 46,458 123,400 $ 0.38 Participating securities 992 4,631 $ 0.21 1,722 4,574 $ 0.38 Total Company $ 27,166 $ 48,180 Nine Months Ended September 30, 2022 2023 Net Income Allocation Shares (1) Basic and Diluted EPS Net Income Allocation Shares (1) Basic and Diluted EPS (in thousands, except for per share amounts) Common shares $ 126,902 125,341 $ 1.01 $ 190,067 122,865 $ 1.55 Participating securities 4,588 4,532 $ 1.01 7,155 4,625 $ 1.55 Total Company $ 131,490 $ 197,222 _______________________________________________________________________________ (1) Represents the weighted average share count outstanding during the period.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Litigation The Company is a party to various legal actions, proceedings, and claims (some of which are not insured), and regulatory and other governmental audits and investigations in the ordinary course of its business. The Company cannot predict the ultimate outcome of pending litigation, proceedings, and regulatory and other governmental audits and investigations. These matters could potentially subject the Company to sanctions, damages, recoupments, fines, and other penalties. The Department of Justice, Centers for Medicare & Medicaid Services (“CMS”), or other federal and state enforcement and regulatory agencies may conduct additional investigations related to the Company’s businesses in the future that may, either individually or in the aggregate, have a material adverse effect on the Company’s business, financial position, results of operations, and liquidity. To address claims arising out of the Company’s operations, the Company maintains professional malpractice liability insurance and general liability insurance coverages through a number of different programs that are dependent upon such factors as the state where the Company is operating and whether the operations are wholly owned or are operated through a joint venture. For the Company’s wholly owned hospital and outpatient clinic operations, the Company currently maintains insurance coverages under a combination of policies with a total annual aggregate limit of up to $37.0 million for professional malpractice liability insurance and $40.0 million for general liability insurance. For the Company’s Concentra center operations, the Company currently maintains insurance coverages under a combination of policies with a total annual aggregate limit of up to $19.0 million for professional malpractice liability insurance and $19.0 million for general liability insurance. The Company’s insurance for the professional liability coverage is written on a “claims-made” basis, and its commercial general liability coverage is maintained on an “occurrence” basis. These coverages apply after a self-insured retention limit is exceeded. For the Company’s joint venture operations, the Company has designed a separate insurance program that responds to the risks of specific joint ventures. Most of the Company’s joint ventures are insured under a master program with an annual aggregate limit of up to $80.0 million, subject to a sublimit aggregate ranging from $23.0 million to $33.0 million. The policies are generally written on a “claims-made” basis. Each of these programs has either a deductible or self-insured retention limit. The Company also maintains additional types of liability insurance covering claims, that due to their nature or amount, are not covered by or not fully covered by the Company’s professional and general liability insurance policies. These insurance policies also do not generally cover punitive damages and are subject to various deductibles and policy limits. The Company reviews its insurance program annually and may make adjustments to the amount of insurance coverage and self-insured retentions in future years. Significant legal actions, as well as the cost and possible lack of available insurance, could subject the Company to substantial uninsured liabilities. In the Company’s opinion, the outcome of these actions, individually or in the aggregate, will not have a material adverse effect on its financial position, results of operations, or cash flows. Healthcare providers are subject to lawsuits under the qui tam provisions of the federal False Claims Act. Qui tam lawsuits typically remain under seal (hence, usually unknown to the defendant) for some time while the government decides whether or not to intervene on behalf of a private qui tam plaintiff (known as a relator) and take the lead in the litigation. These lawsuits can involve significant monetary damages and penalties and award bounties to private plaintiffs who successfully bring the suits. The Company is and has been a defendant in these cases in the past, and may be named as a defendant in similar cases from time to time in the future. Oklahoma City Subpoena. On August 24, 2020, the Company and Select Specialty Hospital – Oklahoma City, Inc. (“SSH–Oklahoma City”) received Civil Investigative Demands (“CIDs”) from the U.S. Attorney’s Office for the Western District of Oklahoma seeking responses to interrogatories and the production of various documents principally relating to the documentation, billing and reviews of medical services furnished to patients at SSH-Oklahoma City. The Company understands that the investigation arose from a qui tam lawsuit alleging billing fraud related to charges for respiratory therapy services at SSH-Oklahoma City and Select Specialty Hospital - Wichita, Inc. The Company has produced documents in response to the CIDs and is fully cooperating with this investigation. At this time, the Company is unable to predict the timing and outcome of this matter. Physical Therapy Billing. On October 7, 2021, the Company received a letter from a Trial Attorney at the U.S. Department of Justice, Civil Division, Commercial Litigation Branch, Fraud Section (“DOJ”) stating that the DOJ, in conjunction with the U.S. Department of Health and Human Services (“HHS”), is investigating the Company in connection with potential violations of the False Claims Act, 31 U.S.C. § 3729, et seq . The letter specified that the investigation relates to the Company’s billing for physical therapy services, and indicated that the DOJ would be requesting certain records from the Company. In 2021, the DOJ requested, and the Company furnished, records relating to six of the Company’s outpatient therapy clinics in Florida. In 2022, the DOJ requested certain data relating to all of the Company’s outpatient therapy clinics nationwide, and sought information about the Company’s ability to produce additional data relating to the physical therapy services furnished by the Company’s outpatient therapy clinics and Concentra. The Company has produced data and other documents requested by the DOJ and is fully cooperating on this investigation. At this time, the Company is unable to predict the timing and outcome of this matter.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On November 2, 2023, the Company’s Board of Directors declared a cash dividend of $0.125 per share. The dividend will be payable on or about November 28, 2023, to stockholders of record as of the close of business on November 15, 2023.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Pay vs Performance Disclosure
Net income attributable to Select Medical Holdings Corporation	$ 48,180	$ 78,237	$ 70,805	$ 27,166	$ 55,207	$ 49,117	$ 197,222	$ 131,490

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Accounting Policies (Policies)

Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Recent Accounting Guidance Not Yet Adopted	Recent Accounting Guidance Not Yet Adopted In March 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-01, Leases (Topic 842): Common Control Arrangements , which requires companies to amortize leasehold improvements associated with related party leases under common control over the useful life of the leasehold improvement to the common control group. The ASU is effective for annual reporting periods beginning on or after December 15, 2023; however, early adoption is permitted. The ASU can either be applied prospectively or retrospectively. The Company is currently evaluating this ASU, but does not expect it to have a material impact on its consolidated financial statements upon adoption. The Company plans to adopt the ASU using the prospective method as of January 1, 2024.
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, liabilities, revenues, and expenses. Actual results could differ from those estimates.
Credit Risk Concentrations	Credit Risk ConcentrationsFinancial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash balances and accounts receivable. 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.Because of the diversity in the Company’s non-governmental third-party payor base, as well as their geographic dispersion, accounts receivable due from the Medicare program represent the Company’s only significant concentration of credit risk.
Redeemable Non-Controlling Interests	Redeemable Non-Controlling InterestsThe ownership interests held by outside parties in subsidiaries, which include 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, after the attribution of net income or loss.
Variable Interest Entities	Variable Interest EntitiesCertain states prohibit the “corporate practice of medicine,” which restricts the Company from owning medical practices which directly employ physicians or therapists and from exercising control over medical decisions by physicians and therapists. In these states, the Company enters into long-term management agreements with medical practices that are owned by licensed physicians or therapists, which, in turn, employ or contract with physicians or therapists who provide professional medical services. The management agreements provide for the Company to direct the transfer of ownership of the medical practices. Based on the provisions of the management agreements, the medical practices are variable interest entities for which the Company is the primary beneficiary.

Redeemable Non-Controlling In_2

Redeemable Non-Controlling Interests (Tables)	9 Months Ended
	Sep. 30, 2023
Noncontrolling Interest [Abstract]
Schedule of redeemable non-controlling interests	The changes in redeemable non-controlling interests are as follows: Nine Months Ended September 30, 2022 2023 (in thousands) Balance as of January 1 $ 39,033 $ 34,043 Net income attributable to redeemable non-controlling interests 1,918 1,641 Distributions to redeemable non-controlling interests (1,198) (1,900) Redemption value adjustment on redeemable non-controlling interests 1,381 436 Other 536 179 Balance as of March 31 $ 41,670 $ 34,399 Net income attributable to redeemable non-controlling interests 1,900 2,084 Distributions to and purchases of redeemable non-controlling interests (1,553) (2,110) Redemption value adjustment on redeemable non-controlling interests (355) 2 Other 535 — Balance as of June 30 $ 42,197 $ 34,375 Net income attributable to redeemable non-controlling interests 2,240 2,320 Distributions to and purchases of redeemable non-controlling interests (7,325) (7,784) Redemption value adjustment on redeemable non-controlling interests (4,108) (1,912) Other 536 — Balance as of September 30 $ 33,540 $ 26,999

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Schedule of lease cost	The Company’s total lease cost is as follows: Three Months Ended September 30, 2022 Three Months Ended September 30, 2023 Unrelated Parties Related Parties Total Unrelated Parties Related Parties Total (in thousands) Operating lease cost $ 73,795 $ 1,810 $ 75,605 $ 78,147 $ 1,834 $ 79,981 Finance lease cost: Amortization of right-of-use assets 381 — 381 387 — 387 Interest on lease liabilities 335 — 335 352 — 352 Short-term lease cost 24 — 24 — — — Variable lease cost 14,855 141 14,996 16,562 — 16,562 Sublease income (1,963) — (1,963) (1,633) — (1,633) Total lease cost $ 87,427 $ 1,951 $ 89,378 $ 93,815 $ 1,834 $ 95,649 Nine Months Ended September 30, 2022 Nine Months Ended September 30, 2023 Unrelated Parties Related Parties Total Unrelated Parties Related Parties Total (in thousands) Operating lease cost $ 221,726 $ 5,428 $ 227,154 $ 231,671 $ 5,501 $ 237,172 Finance lease cost: Amortization of right-of-use assets 1,105 — 1,105 1,185 — 1,185 Interest on lease liabilities 1,011 — 1,011 1,059 — 1,059 Short-term lease cost 74 — 74 — — — Variable lease cost 42,917 321 43,238 48,854 84 48,938 Sublease income (5,869) — (5,869) (5,027) — (5,027) Total lease cost $ 260,964 $ 5,749 $ 266,713 $ 277,742 $ 5,585 $ 283,327

Long-Term Debt and Notes Paya_2

Long-Term Debt and Notes Payable (Tables)	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Schedule of long-term debt and notes payable	As of September 30, 2023, the Company’s long-term debt and notes payable are as follows: Principal Unamortized Premium (Discount) Unamortized Carrying Value Fair Value (in thousands) 6.250% senior notes $ 1,225,000 $ 17,046 $ (8,697) $ 1,233,349 $ 1,193,126 Credit facilities: Revolving facility 340,000 — — 340,000 331,500 Term loan 2,097,743 (12,999) (3,487) 2,081,257 2,087,254 Other debt, including finance leases 75,804 — (81) 75,723 75,723 Total debt $ 3,738,547 $ 4,047 $ (12,265) $ 3,730,329 $ 3,687,603 As of December 31, 2022, the Company’s long-term debt and notes payable are as follows: Principal Unamortized Premium (Discount) Unamortized Carrying Value Fair Value (in thousands) 6.250% senior notes $ 1,225,000 $ 21,555 $ (10,948) $ 1,235,607 $ 1,163,689 Credit facilities: Revolving facility 445,000 — — 445,000 443,331 Term loan 2,103,437 (4,376) (4,771) 2,094,290 2,056,110 Other debt, including finance leases 104,800 — (135) 104,665 104,665 Total debt $ 3,878,237 $ 17,179 $ (15,854) $ 3,879,562 $ 3,767,795
Schedule of principal maturities of long-term debt and notes payable	Principal maturities of the Company’s long-term debt and notes payable are approximately as follows: 2023 2024 2025 2026 2027 Thereafter Total (in thousands) 6.250% senior notes $ — $ — $ — $ 1,225,000 $ — $ — $ 1,225,000 Credit facilities: Revolving facility — — — — 340,000 — 340,000 Term loan 5,258 21,030 21,030 21,030 2,029,395 — 2,097,743 Other debt, including finance leases 5,962 50,988 2,527 2,427 1,941 11,959 75,804 Total debt $ 11,220 $ 72,018 $ 23,557 $ 1,248,457 $ 2,371,336 $ 11,959 $ 3,738,547

Interest Rate Cap (Tables)

Interest Rate Cap (Tables)	9 Months Ended
	Sep. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of accumulated other comprehensive income (loss)	The following table outlines the changes in accumulated other comprehensive income (loss), net of tax, during the periods presented: Nine Months Ended September 30, 2022 2023 (in thousands) Balance as of January 1 $ 12,282 $ 88,602 Gain (loss) on interest rate cap cash flow hedge 39,814 (2,696) Amounts reclassified from accumulated other comprehensive income 39 (13,252) Balance as of March 31 $ 52,135 $ 72,654 Gain on interest rate cap cash flow hedge 11,833 17,527 Amounts reclassified from accumulated other comprehensive income (6) (15,134) Balance as of June 30 $ 63,962 $ 75,047 Gain on interest rate cap cash flow hedge 31,079 3,895 Amounts reclassified from accumulated other comprehensive income (4,485) (16,215) Balance as of September 30 $ 90,556 $ 62,727
Schedule of reclassification out of accumulated other comprehensive income	The effects on net income of amounts reclassified from accumulated other comprehensive income are as follows: Three Months Ended September 30, Nine Months Ended September 30, Statement of Operations 2022 2023 2022 2023 (in thousands) Gains included in interest expense $ 5,980 $ 21,477 $ 5,936 $ 59,074 Income tax expense (1,495) (5,262) (1,484) (14,473) Amounts reclassified from accumulated other comprehensive income $ 4,485 $ 16,215 $ 4,452 $ 44,601

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of interest rate cap	Financial Instrument Balance Sheet Classification Level December 31, 2022 September 30, 2023 Asset: (in thousands) Interest rate cap contract, current portion Current portion of interest rate cap contract Level 2 $ 74,857 $ 85,896 Interest rate cap contract, non-current portion Interest rate cap contract, net of current portion Level 2 45,200 —
Schedule of long-term debt	December 31, 2022 September 30, 2023 Financial Instrument Level Carrying Value Fair Value Carrying Value Fair Value (in thousands) 6.250% senior notes Level 2 $ 1,235,607 $ 1,163,689 $ 1,233,349 $ 1,193,126 Credit facilities: Revolving facility Level 2 445,000 443,331 340,000 331,500 Term loan Level 2 2,094,290 2,056,110 2,081,257 2,087,254

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2023
Segment Reporting [Abstract]
Schedule of selected financial data for reportable segments	The following tables summarize selected financial data for the Company’s reportable segments. Three Months Ended September 30, Nine Months Ended September 30, 2022 2023 2022 2023 (in thousands) Revenue: Critical illness recovery hospital $ 524,584 $ 563,628 $ 1,672,247 $ 1,732,645 Rehabilitation hospital 229,387 247,101 678,908 719,419 Outpatient rehabilitation 284,993 291,804 844,191 890,679 Concentra 444,576 473,964 1,309,356 1,397,341 Other 84,254 89,197 247,380 265,118 Total Company $ 1,567,794 $ 1,665,694 $ 4,752,082 $ 5,005,202 Adjusted EBITDA: Critical illness recovery hospital $ 11,013 $ 46,362 $ 66,999 $ 188,631 Rehabilitation hospital 49,772 53,626 141,996 155,531 Outpatient rehabilitation 25,715 26,346 85,912 89,395 Concentra 90,025 98,907 272,101 293,046 Other (1) (23,412) (31,404) (69,054) (99,234) Total Company $ 153,113 $ 193,837 $ 497,954 $ 627,369 Total assets: Critical illness recovery hospital $ 2,368,968 $ 2,454,578 $ 2,368,968 $ 2,454,578 Rehabilitation hospital 1,189,486 1,222,853 1,189,486 1,222,853 Outpatient rehabilitation 1,377,010 1,401,148 1,377,010 1,401,148 Concentra 2,309,392 2,321,671 2,309,392 2,321,671 Other 310,120 283,758 310,120 283,758 Total Company $ 7,554,976 $ 7,684,008 $ 7,554,976 $ 7,684,008 Purchases of property, equipment, and other assets: Critical illness recovery hospital $ 21,534 $ 21,098 $ 60,631 $ 76,119 Rehabilitation hospital 392 4,813 11,487 15,298 Outpatient rehabilitation 10,098 8,855 28,826 29,263 Concentra 9,074 15,456 28,030 45,702 Other 844 (24) 6,145 2,215 Total Company $ 41,942 $ 50,198 $ 135,119 $ 168,597 _______________________________________________________________________________ (1) For the three and nine months ended September 30, 2023, Adjusted EBITDA included other operating income of $0.5 million. For the three and nine months ended September 30, 2022, Adjusted EBITDA included other operating income of $8.1 million and $23.2 million, respectively. The other operating income was principally related to the recognition of payments received under the Provider Relief Fund for health care related expenses and loss of revenue attributable to COVID-19.
Schedule of reconciliation of Adjusted EBITDA to income before income taxes	A reconciliation of Adjusted EBITDA to income before income taxes is as follows: Three Months Ended September 30, 2022 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Adjusted EBITDA $ 11,013 $ 49,772 $ 25,715 $ 90,025 $ (23,412) Depreciation and amortization (16,055) (6,994) (8,157) (17,781) (2,472) Stock compensation expense — — — (535) (9,652) Income (loss) from operations $ (5,042) $ 42,778 $ 17,558 $ 71,709 $ (35,536) $ 91,467 Equity in earnings of unconsolidated subsidiaries 8,084 Interest expense (45,204) Income before income taxes $ 54,347 Three Months Ended September 30, 2023 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Adjusted EBITDA $ 46,362 $ 53,626 $ 26,346 $ 98,907 $ (31,404) Depreciation and amortization (16,402) (7,106) (8,861) (17,959) (2,066) Stock compensation expense — — — — (11,483) Income (loss) from operations $ 29,960 $ 46,520 $ 17,485 $ 80,948 $ (44,953) $ 129,960 Loss on early retirement of debt (14,692) Equity in earnings of unconsolidated subsidiaries 11,561 Interest expense (50,271) Income before income taxes $ 76,558 Nine Months Ended September 30, 2022 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Adjusted EBITDA $ 66,999 $ 141,996 $ 85,912 $ 272,101 $ (69,054) Depreciation and amortization (45,276) (20,971) (24,316) (55,323) (7,693) Stock compensation expense — — — (1,606) (26,350) Income (loss) from operations $ 21,723 $ 121,025 $ 61,596 $ 215,172 $ (103,097) $ 316,419 Equity in earnings of unconsolidated subsidiaries 19,648 Interest expense (121,770) Income before income taxes $ 214,297 Nine Months Ended September 30, 2023 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Adjusted EBITDA $ 188,631 $ 155,531 $ 89,395 $ 293,046 $ (99,234) Depreciation and amortization (46,925) (20,881) (26,097) (54,552) (6,303) Stock compensation expense — — — (178) (31,812) Income (loss) from operations $ 141,706 $ 134,650 $ 63,298 $ 238,316 $ (137,349) $ 440,621 Loss on early retirement of debt (14,692) Equity in earnings of unconsolidated subsidiaries 30,618 Interest expense (147,839) Income before income taxes $ 308,708

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Schedule of disaggregation of revenue	The following tables disaggregate the Company’s revenue for the three and nine months ended September 30, 2022 and 2023: Three Months Ended September 30, 2022 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Patient service revenue: Medicare $ 201,558 $ 106,584 $ 45,193 $ 205 $ — $ 353,540 Non-Medicare 320,896 111,509 221,275 443,040 — 1,096,720 Total patient services revenues 522,454 218,093 266,468 443,245 — 1,450,260 Other revenue 2,130 11,294 18,525 1,331 84,254 117,534 Total revenue $ 524,584 $ 229,387 $ 284,993 $ 444,576 $ 84,254 $ 1,567,794 Three Months Ended September 30, 2023 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Patient service revenue: Medicare $ 201,881 $ 115,145 $ 45,286 $ 261 $ — $ 362,573 Non-Medicare 360,847 119,524 228,386 472,171 — 1,180,928 Total patient services revenues 562,728 234,669 273,672 472,432 — 1,543,501 Other revenue 900 12,432 18,132 1,532 89,197 122,193 Total revenue $ 563,628 $ 247,101 $ 291,804 $ 473,964 $ 89,197 $ 1,665,694 Nine Months Ended September 30, 2022 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Patient service revenue: Medicare $ 634,225 $ 314,635 $ 131,530 $ 577 $ — $ 1,080,967 Non-Medicare 1,031,000 331,652 660,345 1,304,865 — 3,327,862 Total patient services revenues 1,665,225 646,287 791,875 1,305,442 — 4,408,829 Other revenue 7,022 32,621 52,316 3,914 247,380 343,253 Total revenue $ 1,672,247 $ 678,908 $ 844,191 $ 1,309,356 $ 247,380 $ 4,752,082 Nine Months Ended September 30, 2023 Critical Illness Recovery Hospital Rehabilitation Hospital Outpatient Concentra Other Total (in thousands) Patient service revenue: Medicare $ 639,007 $ 338,650 $ 137,734 $ 754 $ — $ 1,116,145 Non-Medicare 1,090,650 344,885 696,617 1,392,136 — 3,524,288 Total patient services revenues 1,729,657 683,535 834,351 1,392,890 — 4,640,433 Other revenue 2,988 35,884 56,328 4,451 265,118 364,769 Total revenue $ 1,732,645 $ 719,419 $ 890,679 $ 1,397,341 $ 265,118 $ 5,005,202

Earnings per Share (Tables)

Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted earnings per share	The following table sets forth the net income attributable to the Company, its common shares outstanding, and its participating securities outstanding. Basic and Diluted EPS Three Months Ended September 30, Nine Months Ended September 30, 2022 2023 2022 2023 (in thousands) Net income $ 38,126 $ 60,816 $ 160,314 $ 237,933 Less: net income attributable to non-controlling interests 10,960 12,636 28,824 40,711 Net income attributable to the Company 27,166 48,180 131,490 197,222 Less: Distributed and undistributed income attributable to participating securities 992 1,722 4,588 7,155 Distributed and undistributed income attributable to common shares $ 26,174 $ 46,458 $ 126,902 $ 190,067 The following tables set forth the computation of EPS under the two-class method: Three Months Ended September 30, 2022 2023 Net Income Allocation Shares (1) Basic and Diluted EPS Net Income Allocation Shares (1) Basic and Diluted EPS (in thousands, except for per share amounts) Common shares $ 26,174 122,193 $ 0.21 $ 46,458 123,400 $ 0.38 Participating securities 992 4,631 $ 0.21 1,722 4,574 $ 0.38 Total Company $ 27,166 $ 48,180 Nine Months Ended September 30, 2022 2023 Net Income Allocation Shares (1) Basic and Diluted EPS Net Income Allocation Shares (1) Basic and Diluted EPS (in thousands, except for per share amounts) Common shares $ 126,902 125,341 $ 1.01 $ 190,067 122,865 $ 1.55 Participating securities 4,588 4,532 $ 1.01 7,155 4,625 $ 1.55 Total Company $ 131,490 $ 197,222 _______________________________________________________________________________ (1) Represents the weighted average share count outstanding during the period.

Credit Risk Concentrations (Det

Credit Risk Concentrations (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Medicare Receivable | Credit Concentration Risk | Accounts Receivable
Concentration Risk [Line Items]
Percentage of concentration risk	15%	19%

Redeemable Non-Controlling In_3

Redeemable Non-Controlling Interests - Schedule of Redeemable Non-Controlling Interests (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance, beginning	$ 34,375	$ 34,399	$ 34,043	$ 42,197	$ 41,670	$ 39,033
Net income attributable to redeemable non-controlling interests	2,320	2,084	1,641	2,240	1,900	1,918
Distributions to and purchases of redeemable non-controlling interests	(7,784)	(2,110)	(1,900)	(7,325)	(1,553)	(1,198)
Redemption value adjustment on redeemable non-controlling interests	(1,912)	2	436	(4,108)	(355)	1,381
Other	0	0	179	536	535	536
Balance, ending	$ 26,999	$ 34,375	$ 34,399	$ 33,540	$ 42,197	$ 41,670

Variable Interest Entities (Det

Variable Interest Entities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Variable Interest Entity [Line Items]
Assets	$ 7,684,008	$ 7,665,293	$ 7,554,976
Liabilities	6,133,620	6,274,686
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	273,400	232,100
Liabilities	85,800	78,800
Variable Interest Entity, Primary Beneficiary | Related Party
Variable Interest Entity [Line Items]
Obligations payable	$ 195,100	$ 158,300

Leases - Schedule of Lease Cost

Leases - Schedule of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating lease cost
Unrelated Parties	$ 78,147	$ 73,795	$ 231,671	$ 221,726
Related Parties	1,834	1,810	5,501	5,428
Total	79,981	75,605	237,172	227,154
Amortization of right-of-use assets
Unrelated Parties	387	381	1,185	1,105
Related Parties	0	0	0	0
Total	387	381	1,185	1,105
Interest on lease liabilities
Unrelated Parties	352	335	1,059	1,011
Related Parties	0	0	0	0
Total	352	335	1,059	1,011
Short-term lease cost
Unrelated Parties	0	24	0	74
Related Parties	0	0	0	0
Total	0	24	0	74
Variable lease cost
Unrelated Parties	16,562	14,855	48,854	42,917
Related Parties	0	141	84	321
Total	16,562	14,996	48,938	43,238
Sublease income
Unrelated Parties	(1,633)	(1,963)	(5,027)	(5,869)
Related Parties	0	0	0	0
Total	(1,633)	(1,963)	(5,027)	(5,869)
Total lease cost
Unrelated Parties	93,815	87,427	277,742	260,964
Related Parties	1,834	1,951	5,585	5,749
Total	$ 95,649	$ 89,378	$ 283,327	$ 266,713

Long-Term Debt and Notes Paya_3

Long-Term Debt and Notes Payable - Components of Long-Term Debt And Notes Payable (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Principal Outstanding	$ 3,738,547	$ 3,878,237
Unamortized Premium (Discount)	4,047	17,179
Unamortized Issuance Costs	(12,265)	(15,854)
Carrying Value	3,730,329	3,879,562
Fair Value	$ 3,687,603	$ 3,767,795
Senior notes | 6.250% senior notes
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	6.25%	6.25%
Principal Outstanding	$ 1,225,000	$ 1,225,000
Unamortized Premium (Discount)	17,046	21,555
Unamortized Issuance Costs	(8,697)	(10,948)
Carrying Value	1,233,349	1,235,607
Fair Value	1,193,126	1,163,689
Term loan
Debt Instrument [Line Items]
Principal Outstanding	2,097,743	2,103,437
Unamortized Premium (Discount)	(12,999)	(4,376)
Unamortized Issuance Costs	(3,487)	(4,771)
Carrying Value	2,081,257	2,094,290
Fair Value	2,087,254	2,056,110
Other debt, including finance leases
Debt Instrument [Line Items]
Principal Outstanding	75,804	104,800
Unamortized Premium (Discount)	0	0
Unamortized Issuance Costs	(81)	(135)
Carrying Value	75,723	104,665
Fair Value	75,723	104,665
Revolving facility | Revolving facility
Debt Instrument [Line Items]
Principal Outstanding	340,000	445,000
Unamortized Premium (Discount)	0	0
Unamortized Issuance Costs	0	0
Carrying Value	340,000	445,000
Fair Value	$ 331,500	$ 443,331

Long-Term Debt and Notes Paya_4

Long-Term Debt and Notes Payable - Principal Maturities Of Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
2023	$ 11,220
2024	72,018
2025	23,557
2026	1,248,457
2027	2,371,336
Thereafter	11,959
Total	$ 3,738,547	$ 3,878,237
Senior notes | 6.250% senior notes
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	6.25%	6.25%
2023	$ 0
2024	0
2025	0
2026	1,225,000
2027	0
Thereafter	0
Total	1,225,000	$ 1,225,000
Revolving facility | Revolving facility
Debt Instrument [Line Items]
2023	0
2024	0
2025	0
2026	0
2027	340,000
Thereafter	0
Total	340,000	445,000
Term loan
Debt Instrument [Line Items]
2023	5,258
2024	21,030
2025	21,030
2026	21,030
2027	2,029,395
Thereafter	0
Total	2,097,743	2,103,437
Other debt, including finance leases
Debt Instrument [Line Items]
2023	5,962
2024	50,988
2025	2,527
2026	2,427
2027	1,941
Thereafter	11,959
Total	$ 75,804	$ 104,800

Long-Term Debt and Notes Paya_5

Long-Term Debt and Notes Payable - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jul. 31, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Aug. 31, 2023	Jul. 30, 2023
Line of Credit Facility [Line Items]
Loss on early retirement of debt		$ 14,692	$ 0	$ 14,692	$ 0
Amendment No. 8 To Select Credit Agreement
Line of Credit Facility [Line Items]
Spring maturity period (in days)	90 days
Principal outstanding	$ 300,000
Loss on early retirement of debt		$ 14,700
Term loan | Amendment No. 8 To Select Credit Agreement
Line of Credit Facility [Line Items]
Aggregate principal amount	$ 2,103,000
Term loan | Amendment No. 8 To Select Credit Agreement | Term Secured Overnight Financing Rate
Line of Credit Facility [Line Items]
Basis spread	3%
Revolving facility | Revolving facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity							$ 650,000
Revolving facility | Revolving facility | Amendment No. 8 To Select Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 710,000
Revolving facility | Revolving facility | Amendment No. 8 To Select Credit Agreement | Adjusted Term SOFR
Line of Credit Facility [Line Items]
Basis spread	2.50%
Credit spread adjustment	0.10%
Revolving facility | Revolving facility | Amendment No. 9 To Select Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity						$ 770,000

Interest Rate Cap - Narrative (

Interest Rate Cap - Narrative (Details) - Interest Rate Cap $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)
Derivative [Line Items]
Derivative cap interest rate (as a percent)	1%
Notional amount	$ 2,000
Annual premium (in percent)	0.000916
Annual premium amount	$ 1.8
Estimated pre-tax gain expected to be reclassified in the next twelve months	$ 83

Interest Rate Cap - Schedule of

Interest Rate Cap - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 1,501,579	$ 1,418,441	$ 1,356,564	$ 1,303,701	$ 1,366,896	$ 1,325,902
Ending balance	1,523,389	1,501,579	1,418,441	1,334,519	1,303,701	1,366,896
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Interest Rate Cap
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	75,047	72,654	88,602	63,962	52,135	12,282
Gain (loss) on interest rate cap cash flow hedge	3,895	17,527	(2,696)	31,079	11,833	39,814
Amounts reclassified from accumulated other comprehensive income	(16,215)	(15,134)	(13,252)	(4,485)	(6)	39
Ending balance	$ 62,727	$ 75,047	$ 72,654	$ 90,556	$ 63,962	$ 52,135

Interest Rate Cap - Schedule _2

Interest Rate Cap - Schedule of Reclassification out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Gains included in interest expense	$ (50,271)			$ (45,204)			$ (147,839)	$ (121,770)
Income tax expense	(15,742)			(16,221)			(70,775)	(53,983)
Amounts reclassified from accumulated other comprehensive income	48,180	$ 78,237	$ 70,805	27,166	$ 55,207	$ 49,117	197,222	131,490
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Interest Rate Cap
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Gains included in interest expense	21,477			5,980			59,074	5,936
Income tax expense	(5,262)			(1,495)			(14,473)	(1,484)
Amounts reclassified from accumulated other comprehensive income	$ 16,215			$ 4,485			$ 44,601	$ 4,452

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Schedule of Interest Rate Cap (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate cap contract, current portion	$ 85,896	$ 74,857
Interest rate cap contract, non-current portion	0	45,200
Interest Rate Cap | Fair Value, Inputs, Level 2 | Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate cap contract, current portion	85,896	74,857
Interest rate cap contract, non-current portion	$ 0	$ 45,200

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 3,687,603	$ 3,767,795
Senior notes | 6.250% senior notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate of debt (as a percent)	6.25%	6.25%
Carrying Value	$ 1,233,349	$ 1,235,607
Fair Value	1,193,126	1,163,689
Senior notes | Fair Value, Inputs, Level 2 | 6.250% senior notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	1,233,349	1,235,607
Fair Value	1,193,126	1,163,689
Revolving facility | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	340,000	445,000
Fair Value	331,500	443,331
Term loan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	2,081,257	2,094,290
Fair Value	2,087,254	2,056,110
Term loan | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	2,081,257	2,094,290
Fair Value	$ 2,087,254	$ 2,056,110

Segment Information - Selected

Segment Information - Selected Financial Data (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Segment Reporting Information [Line Items]
Revenue	$ 1,665,694	$ 1,567,794	$ 5,005,202	$ 4,752,082
Adjusted EBITDA	193,837	153,113	627,369	497,954
Total assets	7,684,008	7,554,976	7,684,008	7,554,976	$ 7,665,293
Purchases of property, equipment, and other assets	50,198	41,942	168,597	135,119
Other operating income	485	8,440	1,211	23,565
Operating Segments | Critical Illness Recovery Hospital
Segment Reporting Information [Line Items]
Revenue	563,628	524,584	1,732,645	1,672,247
Adjusted EBITDA	46,362	11,013	188,631	66,999
Total assets	2,454,578	2,368,968	2,454,578	2,368,968
Purchases of property, equipment, and other assets	21,098	21,534	76,119	60,631
Operating Segments | Rehabilitation Hospital
Segment Reporting Information [Line Items]
Revenue	247,101	229,387	719,419	678,908
Adjusted EBITDA	53,626	49,772	155,531	141,996
Total assets	1,222,853	1,189,486	1,222,853	1,189,486
Purchases of property, equipment, and other assets	4,813	392	15,298	11,487
Operating Segments | Outpatient Rehabilitation
Segment Reporting Information [Line Items]
Revenue	291,804	284,993	890,679	844,191
Adjusted EBITDA	26,346	25,715	89,395	85,912
Total assets	1,401,148	1,377,010	1,401,148	1,377,010
Purchases of property, equipment, and other assets	8,855	10,098	29,263	28,826
Operating Segments | Concentra
Segment Reporting Information [Line Items]
Revenue	473,964	444,576	1,397,341	1,309,356
Adjusted EBITDA	98,907	90,025	293,046	272,101
Total assets	2,321,671	2,309,392	2,321,671	2,309,392
Purchases of property, equipment, and other assets	15,456	9,074	45,702	28,030
Other
Segment Reporting Information [Line Items]
Revenue	89,197	84,254	265,118	247,380
Adjusted EBITDA	(31,404)	(23,412)	(99,234)	(69,054)
Total assets	283,758	310,120	283,758	310,120
Purchases of property, equipment, and other assets	(24)	844	2,215	6,145
Other operating income	$ 500		$ 500
Government assistance recognized in earnings, CARES Act		$ 8,100		$ 23,200

Segment Information - Reconcili

Segment Information - Reconciliation of Adjusted EBITDA to Income Before Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 193,837	$ 153,113	$ 627,369	$ 497,954
Depreciation and amortization	(52,394)	(51,459)	(154,758)	(153,579)
Income from operations	129,960	91,467	440,621	316,419
Loss on early retirement of debt	(14,692)	0	(14,692)	0
Equity in earnings of unconsolidated subsidiaries	11,561	8,084	30,618	19,648
Interest expense	(50,271)	(45,204)	(147,839)	(121,770)
Income before income taxes	76,558	54,347	308,708	214,297
Operating Segments | Critical Illness Recovery Hospital
Segment Reporting Information [Line Items]
Adjusted EBITDA	46,362	11,013	188,631	66,999
Depreciation and amortization	(16,402)	(16,055)	(46,925)	(45,276)
Stock compensation expense	0	0	0	0
Income from operations	29,960	(5,042)	141,706	21,723
Operating Segments | Rehabilitation Hospital
Segment Reporting Information [Line Items]
Adjusted EBITDA	53,626	49,772	155,531	141,996
Depreciation and amortization	(7,106)	(6,994)	(20,881)	(20,971)
Stock compensation expense	0	0	0	0
Income from operations	46,520	42,778	134,650	121,025
Operating Segments | Outpatient Rehabilitation
Segment Reporting Information [Line Items]
Adjusted EBITDA	26,346	25,715	89,395	85,912
Depreciation and amortization	(8,861)	(8,157)	(26,097)	(24,316)
Stock compensation expense	0	0	0	0
Income from operations	17,485	17,558	63,298	61,596
Operating Segments | Concentra
Segment Reporting Information [Line Items]
Adjusted EBITDA	98,907	90,025	293,046	272,101
Depreciation and amortization	(17,959)	(17,781)	(54,552)	(55,323)
Stock compensation expense	0	(535)	(178)	(1,606)
Income from operations	80,948	71,709	238,316	215,172
Other
Segment Reporting Information [Line Items]
Adjusted EBITDA	(31,404)	(23,412)	(99,234)	(69,054)
Depreciation and amortization	(2,066)	(2,472)	(6,303)	(7,693)
Stock compensation expense	(11,483)	(9,652)	(31,812)	(26,350)
Income from operations	$ (44,953)	$ (35,536)	$ (137,349)	$ (103,097)

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Total revenue	$ 1,665,694	$ 1,567,794	$ 5,005,202	$ 4,752,082
Total patient services revenues
Disaggregation of Revenue [Line Items]
Total revenue	1,543,501	1,450,260	4,640,433	4,408,829
Medicare
Disaggregation of Revenue [Line Items]
Total revenue	362,573	353,540	1,116,145	1,080,967
Non-Medicare
Disaggregation of Revenue [Line Items]
Total revenue	1,180,928	1,096,720	3,524,288	3,327,862
Other revenue
Disaggregation of Revenue [Line Items]
Total revenue	122,193	117,534	364,769	343,253
Operating Segments | Critical Illness Recovery Hospital
Disaggregation of Revenue [Line Items]
Total revenue	563,628	524,584	1,732,645	1,672,247
Operating Segments | Critical Illness Recovery Hospital | Total patient services revenues
Disaggregation of Revenue [Line Items]
Total revenue	562,728	522,454	1,729,657	1,665,225
Operating Segments | Critical Illness Recovery Hospital | Medicare
Disaggregation of Revenue [Line Items]
Total revenue	201,881	201,558	639,007	634,225
Operating Segments | Critical Illness Recovery Hospital | Non-Medicare
Disaggregation of Revenue [Line Items]
Total revenue	360,847	320,896	1,090,650	1,031,000
Operating Segments | Critical Illness Recovery Hospital | Other revenue
Disaggregation of Revenue [Line Items]
Total revenue	900	2,130	2,988	7,022
Operating Segments | Rehabilitation Hospital
Disaggregation of Revenue [Line Items]
Total revenue	247,101	229,387	719,419	678,908
Operating Segments | Rehabilitation Hospital | Total patient services revenues
Disaggregation of Revenue [Line Items]
Total revenue	234,669	218,093	683,535	646,287
Operating Segments | Rehabilitation Hospital | Medicare
Disaggregation of Revenue [Line Items]
Total revenue	115,145	106,584	338,650	314,635
Operating Segments | Rehabilitation Hospital | Non-Medicare
Disaggregation of Revenue [Line Items]
Total revenue	119,524	111,509	344,885	331,652
Operating Segments | Rehabilitation Hospital | Other revenue
Disaggregation of Revenue [Line Items]
Total revenue	12,432	11,294	35,884	32,621
Operating Segments | Outpatient Rehabilitation
Disaggregation of Revenue [Line Items]
Total revenue	291,804	284,993	890,679	844,191
Operating Segments | Outpatient Rehabilitation | Total patient services revenues
Disaggregation of Revenue [Line Items]
Total revenue	273,672	266,468	834,351	791,875
Operating Segments | Outpatient Rehabilitation | Medicare
Disaggregation of Revenue [Line Items]
Total revenue	45,286	45,193	137,734	131,530
Operating Segments | Outpatient Rehabilitation | Non-Medicare
Disaggregation of Revenue [Line Items]
Total revenue	228,386	221,275	696,617	660,345
Operating Segments | Outpatient Rehabilitation | Other revenue
Disaggregation of Revenue [Line Items]
Total revenue	18,132	18,525	56,328	52,316
Operating Segments | Concentra
Disaggregation of Revenue [Line Items]
Total revenue	473,964	444,576	1,397,341	1,309,356
Operating Segments | Concentra | Total patient services revenues
Disaggregation of Revenue [Line Items]
Total revenue	472,432	443,245	1,392,890	1,305,442
Operating Segments | Concentra | Medicare
Disaggregation of Revenue [Line Items]
Total revenue	261	205	754	577
Operating Segments | Concentra | Non-Medicare
Disaggregation of Revenue [Line Items]
Total revenue	472,171	443,040	1,392,136	1,304,865
Operating Segments | Concentra | Other revenue
Disaggregation of Revenue [Line Items]
Total revenue	1,532	1,331	4,451	3,914
Other
Disaggregation of Revenue [Line Items]
Total revenue	89,197	84,254	265,118	247,380
Other | Total patient services revenues
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Other | Medicare
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Other | Non-Medicare
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0	0
Other | Other revenue
Disaggregation of Revenue [Line Items]
Total revenue	$ 89,197	$ 84,254	$ 265,118	$ 247,380

Earnings per Share - Narrative

Earnings per Share - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Contractual dividends paid	$ 0	$ 0	$ 0	$ 0

Earnings per Share - Net Income

Earnings per Share - Net Income Attributable to the Company, Common Shares Outstanding, and Participating Securities Outstanding (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Net income	$ 60,816			$ 38,126			$ 237,933	$ 160,314
Less: Net income attributable to non-controlling interests	12,636			10,960			40,711	28,824
Net income attributable to Select Medical Holdings Corporation	48,180	$ 78,237	$ 70,805	27,166	$ 55,207	$ 49,117	197,222	131,490
Basic EPS
Less: Distributed and undistributed income attributable to participating securities - Basic EPS	1,722			992			7,155	4,588
Distributed and undistributed income attributable to common shares	46,458			26,174			190,067	126,902
Diluted EPS
Less: Distributed and undistributed income attributable to participating securities - Diluted EPS	1,722			992			7,155	4,588
Distributed and undistributed income attributable to common shares	$ 46,458			$ 26,174			$ 190,067	$ 126,902

Earnings per Share - Computatio

Earnings per Share - Computation of EPS Under the Two-Class Method (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Net Income Allocation
Net income allocated to common shares - basic	$ 46,458			$ 26,174			$ 190,067	$ 126,902
Participating securities - basic	1,722			992			7,155	4,588
Net income allocated to common shares - diluted	46,458			26,174			190,067	126,902
Participating securities - diluted	1,722			992			7,155	4,588
Net income attributable to Select Medical Holdings Corporation	$ 48,180	$ 78,237	$ 70,805	$ 27,166	$ 55,207	$ 49,117	$ 197,222	$ 131,490
Weighted average common shares outstanding, basic (in shares)	123,400			122,193			122,865	125,341
Weighted average common shares outstanding, diluted (in shares)	123,400			122,193			122,865	125,341
Weighted average participating securities outstanding (in shares)	4,574			4,631			4,625	4,532
Basic EPS
Basic EPS (in dollars per share)	$ 0.38			$ 0.21			$ 1.55	$ 1.01
Diluted EPS
Diluted EPS (in dollars per share)	$ 0.38			$ 0.21			$ 1.55	$ 1.01

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)
Professional liability claims | Critical Illness Recovery Hospitals, Rehabilitation Hospitals And Outpatient Rehabilitiation
Commitments and Contingencies
Total annual aggregate limit of insurance coverage	$ 37
Professional liability claims | Concentra
Commitments and Contingencies
Total annual aggregate limit of insurance coverage	19
Professional liability claims | Joint Venture Operations
Commitments and Contingencies
Total annual aggregate limit of insurance coverage	80
Professional liability claims | Joint Venture Operations | Minimum
Commitments and Contingencies
Total annual aggregate limit of insurance coverage	23
Professional liability claims | Joint Venture Operations | Maximum
Commitments and Contingencies
Total annual aggregate limit of insurance coverage	33
General Liability | Critical Illness Recovery Hospitals, Rehabilitation Hospitals And Outpatient Rehabilitiation
Commitments and Contingencies
Total annual aggregate limit of insurance coverage	40
General Liability | Concentra
Commitments and Contingencies
Total annual aggregate limit of insurance coverage	$ 19

Subsequent Events (Details)

Subsequent Events (Details)	Nov. 02, 2023 $ / shares
Subsequent Event
Subsequent Event [Line Items]
Cash dividend declared (in dollars per share)	$ 0.125