Subsequent Events - Amendment to the Concentra Credit Facilities (Details) - Concentra Inc - Credit facilities	Oct. 26, 2018	Feb. 01, 2018	Jun. 01, 2015
Term loans | Adjusted LIBO
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)		2.75%
Term loans | Alternate Base Rate
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)		1.75%
Minimum | Revolving facility | Adjusted LIBO
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)			2.75%
Minimum | Revolving facility | Alternate Base Rate
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)			1.75%
Maximum | Revolving facility | Adjusted LIBO
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)			3.00%
Maximum | Revolving facility | Alternate Base Rate
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)			2.00%
Subsequent Event | Term loans | Adjusted LIBO
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)	2.75%
Subsequent Event | Term loans | Alternate Base Rate
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)	1.75%
Subsequent Event | Minimum | Term loans | Adjusted LIBO
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)	2.50%
Subsequent Event | Minimum | Term loans | Alternate Base Rate
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)	1.50%
Subsequent Event | Minimum | Revolving facility | Adjusted LIBO
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)	2.25%
Subsequent Event | Minimum | Revolving facility | Alternate Base Rate
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)	1.25%
Subsequent Event | Maximum | Term loans | Adjusted LIBO
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)	2.75%
Subsequent Event | Maximum | Term loans | Alternate Base Rate
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)	1.75%
Subsequent Event | Maximum | Revolving facility | Adjusted LIBO
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)	2.50%
Subsequent Event | Maximum | Revolving facility | Alternate Base Rate
Line of Credit Facility [Line Items]
Interest rate margin (as a percent)	1.50%