Long-Term Debt and Notes Payable - Principal Maturities Of Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Aug. 01, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
2019	$ 5,177
2020	12,696
2021	8,144
2022	1,261,442
2023	5,401
Thereafter	2,105,172
Total	$ 3,398,032		$ 3,338,381
Senior Notes | 6.25% Senior Notes Due August 15, 2026
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	6.25%
Select Medical Corporation
Debt Instrument [Line Items]
2019	$ 4,791
2020	10,502
2021	6,814
2022	23,036
2023	5,038
Thereafter	2,101,703
Total	$ 2,151,884		1,916,290
Select Medical Corporation | Senior Notes | 6.25% Senior Notes Due August 15, 2026
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	6.25%	6.25%
2019	$ 0
2020	0
2021	0
2022	0
2023	0
Thereafter	550,000
Total	550,000
Select Medical Corporation | Credit facilities | Term loans
Debt Instrument [Line Items]
2019	1,250
2020	5,000
2021	5,000
2022	5,000
2023	5,000
Thereafter	1,509,818
Total	1,531,068		1,129,875
Select Medical Corporation | Other debt, including finance leases
Debt Instrument [Line Items]
2019	3,541
2020	5,502
2021	1,814
2022	18,036
2023	38
Thereafter	41,885
Total	70,816		56,415
Concentra Inc
Debt Instrument [Line Items]
2019	386
2020	2,194
2021	1,330
2022	1,238,406
2023	363
Thereafter	3,469
Total	1,246,148		1,422,091
Concentra Inc | Credit facilities | Term loans
Debt Instrument [Line Items]
2019	250
2020	1,000
2021	1,000
2022	1,238,048
2023	0
Thereafter	0
Total	1,240,298		1,414,175
Concentra Inc | Other debt, including finance leases
Debt Instrument [Line Items]
2019	136
2020	1,194
2021	330
2022	358
2023	363
Thereafter	3,469
Total	$ 5,850		$ 7,916