Segment Reporting - Table 1 (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Net operating revenues	$ 995.6	$ 926.8	$ 2,951.7	$ 2,757.3
Less: Provision for doubtful accounts			(42.7)	(46.7)
Net operating revenues less provision for doubtful accounts	983.0	912.0	2,909.0	2,710.6
Costs and Expenses [Abstract]
Salaries and benefits	542.1	497.4	1,600.0	1,469.6
Other operating expenses	137.6	126.3	397.2	367.0
Supplies	36.5	34.8	110.6	104.2
Occupancy costs	18.6	17.6	54.8	53.5
Total operating expenses	820.7	749.9	2,428.4	2,221.6
Other income	(1.0)	(0.8)	(2.9)	(2.1)
Equity in net income of nonconsolidated affiliates	(2.1)	(2.5)	(6.2)	(7.3)
Net income attributable to noncontrolling interests	19.2	16.4	53.2	53.7
Inpatient Rehabilitation Segment [Member]
Segment Reporting Information [Line Items]
Net operating revenues	794.8	751.7	2,377.3	2,253.5
Less: Provision for doubtful accounts	(11.3)	(13.7)	(38.4)	(43.8)
Net operating revenues less provision for doubtful accounts	783.5	738.0	2,338.9	2,209.7
Costs and Expenses [Abstract]
Salaries and benefits	403.2	371.2	1,195.7	1,107.2
Other operating expenses	117.4	110.1	342.1	321.7
Supplies	33.1	31.9	100.6	96.1
Occupancy costs	15.7	15.0	46.3	46.0
Total operating expenses	569.4	528.2	1,684.7	1,571.0
Other income	(1.0)	(0.8)	(2.9)	(2.1)
Equity in net income of nonconsolidated affiliates	(1.9)	(2.3)	(5.6)	(6.7)
Net income attributable to noncontrolling interests	16.7	14.3	48.6	47.9
Segment Adjusted EBITDA	200.3	198.6	614.1	599.6
Capital Expenditures	59.1	42.7	164.7	128.9
Home Health and Hospice Segment [Member]
Segment Reporting Information [Line Items]
Net operating revenues	200.8	175.1	574.4	503.8
Less: Provision for doubtful accounts	(1.3)	(1.1)	(4.3)	(2.9)
Net operating revenues less provision for doubtful accounts	199.5	174.0	570.1	500.9
Costs and Expenses [Abstract]
Cost of services sold (excluding depreciation and amortization)	93.5	86.8	271.2	246.8
Support and overhead costs	68.9	59.5	203.4	174.5
Total operating expenses	162.4	146.3	474.6	421.3
Other income	0.0	0.0	0.0	0.0
Equity in net income of nonconsolidated affiliates	(0.2)	(0.2)	(0.6)	(0.6)
Net income attributable to noncontrolling interests	2.5	2.1	4.6	5.8
Segment Adjusted EBITDA	34.8	25.8	91.5	74.4
Capital Expenditures	$ 1.7	$ 2.2	$ 5.6	$ 4.6