Segment Information - Reconciliation of Adjusted EBITDA to Income Before Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								7 Months Ended	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment information
Adjusted EBITDA										$ 399,165	$ 363,872	$ 372,861
Depreciation and amortization										(104,981)	(68,354)	(64,392)
Stock compensation expense										(14,679)	(11,042)	(7,033)
Income (loss) from operations	$ 62,300	$ 48,214	$ 85,011	$ 79,265	$ 57,822	$ 66,017	$ 82,193	$ 78,444		274,790	284,476	301,436
Loss on early retirement of debt											(2,277)	(18,747)
Gain on sale of equity investment										29,647
Equity in earnings of unconsolidated subsidiaries										16,811	7,044	2,476
Interest expense										(112,816)	(85,446)	(87,364)
Income before income taxes										208,432	203,797	197,801
Select
Segment information
Depreciation and amortization										(104,981)	(68,354)	(64,392)
Income (loss) from operations	$ 62,300	$ 48,214	$ 85,011	$ 79,265	$ 57,822	$ 66,017	$ 82,193	$ 78,444		274,790	284,476	301,436
Loss on early retirement of debt											(2,277)	(17,788)
Gain on sale of equity investment										29,647
Equity in earnings of unconsolidated subsidiaries										16,811	7,044	2,476
Interest expense										(112,816)	(85,446)	(84,954)
Income before income taxes										208,432	203,797	201,170
Operating Segments | Specialty Hospitals
Segment information
Adjusted EBITDA										327,623	341,787	353,843
Depreciation and amortization										(53,992)	(51,786)	(48,621)
Income (loss) from operations										273,631	290,001	305,222
Operating Segments | Outpatient Rehabilitation
Segment information
Adjusted EBITDA										98,220	97,584	90,313
Depreciation and amortization										(13,053)	(12,845)	(12,024)
Income (loss) from operations										85,167	84,739	78,289
Operating Segments | Concentra
Segment information
Adjusted EBITDA									$ 48,301
Depreciation and amortization									(33,644)
Stock compensation expense									(1,016)
Concentra acquisition costs									(4,715)
Income (loss) from operations									$ 8,926
Other
Segment information
Adjusted EBITDA										(74,979)	(75,499)	(71,295)
Depreciation and amortization										(4,292)	(3,723)	(3,747)
Stock compensation expense										(13,663)	(11,042)	(7,033)
Income (loss) from operations										$ (92,934)	$ (90,264)	$ (82,075)