Financial Information for Subsidiary Guarantors and Non-Guarantor Subsidiaries under Select's 6.375% Senior Notes - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating activities
Net income	$ 220,645	$ 125,270	$ 135,996
Adjustments to reconcile net income to net cash provided by operating activities:
Distributions from unconsolidated subsidiaries	20,006	20,476	13,969
Depreciation and amortization	160,011	145,311	104,981
Provision for bad debts	79,491	69,093	59,372
Equity in earnings of unconsolidated subsidiaries	(21,054)	(19,943)	(16,811)
Loss on extinguishment of debt	6,527	11,626	0
Loss (gain) on sale of assets and businesses	(10,349)	(46,488)	(1,098)
Gain on sale of equity investment	0	(2,779)	(29,647)
Impairment of equity investment	0	5,339	0
Stock compensation expense	19,284	17,413	14,985
Amortization of debt discount, premium and issuance costs	11,130	15,656	9,543
Deferred income taxes	(72,324)	(12,591)	(2,058)
Changes in operating assets and liabilities, net of effects of business combinations:
Accounts receivable	(197,191)	(39,320)	(92,572)
Other current assets	1,597	17,450	(2,503)
Other assets	(886)	9,290	4,713
Accounts payable	3,903	(15,492)	2,345
Accrued expenses	17,341	46,292	7,200
Net cash provided by operating activities	238,131	346,603	208,415
Investing activities
Business combinations, net of cash acquired	(27,390)	(472,206)	(1,061,628)
Purchases of property and equipment	(233,243)	(161,633)	(182,642)
Investment in businesses	(12,682)	(4,723)	(2,347)
Proceeds from sale of equity investment	0	3,779	33,096
Proceeds from sale of assets and businesses	80,350	80,463	1,767
Net cash used in investing activities	(192,965)	(554,320)	(1,211,754)
Financing activities
Borrowings on revolving facilities	970,000	575,000	1,135,000
Payments on revolving facilities	(960,000)	(655,000)	(895,000)
Proceeds from term loans	1,139,487	795,344	623,575
Payments on term loans	(1,179,442)	(438,034)	(29,134)
Revolving facility debt issuance costs	(4,392)	0	0
Borrowings of other debt	46,621	27,721	13,374
Principal payments on other debt	(20,647)	(21,401)	(18,136)
Tax benefit from stock based awards	0	0	1,846
Increase (decrease) in overdrafts	(9,899)	10,746	6,869
Proceeds from issuance of non-controlling interests	9,982	11,846	217,065
Purchase of non-controlling interests	(120)	(2,099)	(1,095)
Distributions to non-controlling interests	(10,500)	(10,555)	(12,637)
Net cash provided by (used in) financing activities	(21,646)	292,311	1,014,420
Net increase in cash and cash equivalents	23,520	84,594	11,081
Cash and cash equivalents at beginning of period	99,029	14,435	3,354
Cash and cash equivalents at end of period	122,549	99,029	14,435
Eliminations
Operating activities
Net income	(193,209)	(105,506)	(140,046)
Adjustments to reconcile net income to net cash provided by operating activities:
Distributions from unconsolidated subsidiaries	0	0	0
Depreciation and amortization	0	0	0
Provision for bad debts	0	0	0
Equity in earnings of unconsolidated subsidiaries	0	0	0
Equity in earnings of consolidated subsidiaries	193,209	105,506	140,046
Loss on extinguishment of debt	0	0
Loss (gain) on sale of assets and businesses	0	0	0
Gain on sale of equity investment		0	0
Impairment of equity investment		0
Stock compensation expense	0	0	0
Amortization of debt discount, premium and issuance costs	0	0	0
Deferred income taxes	0	0	0
Changes in operating assets and liabilities, net of effects of business combinations:
Accounts receivable	0	0	0
Other current assets	0	0	0
Other assets	0	0	0
Accounts payable	0	0	0
Accrued expenses	0	0	0
Net cash provided by operating activities	0	0	0
Investing activities
Business combinations, net of cash acquired	0	0	0
Purchases of property and equipment	0	0	0
Investment in businesses	0	0	0
Proceeds from sale of equity investment		0	0
Proceeds from sale of assets and businesses	0	0	0
Net cash used in investing activities	0	0	0
Financing activities
Borrowings on revolving facilities	0	0	0
Payments on revolving facilities	0	0	0
Proceeds from term loans	0	0	0
Payments on term loans	0	0	0
Revolving facility debt issuance costs	0
Borrowings of other debt	0	0	0
Principal payments on other debt	0	0	0
Dividends paid to Holdings	0	0	0
Equity investment by Holdings	0	0	0
Intercompany	0	0	0
Tax benefit from stock based awards			0
Increase (decrease) in overdrafts	0	0	0
Proceeds from issuance of non-controlling interests	0	0	0
Purchase of non-controlling interests	0	0	0
Distributions to non-controlling interests	0	0	0
Net cash provided by (used in) financing activities	0	0	0
Net increase in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of period	0	0	0
Cash and cash equivalents at end of period	0	0	0
Select (Parent Company Only) | Reportable legal entities
Operating activities
Net income	177,184	115,411	130,736
Adjustments to reconcile net income to net cash provided by operating activities:
Distributions from unconsolidated subsidiaries	0	0	0
Depreciation and amortization	7,540	5,348	4,292
Provision for bad debts	0	0	0
Equity in earnings of unconsolidated subsidiaries	0	0	0
Equity in earnings of consolidated subsidiaries	(179,621)	(113,567)	(132,519)
Loss on extinguishment of debt	6,527	773
Loss (gain) on sale of assets and businesses	(939)	(33,738)	0
Gain on sale of equity investment		0	0
Impairment of equity investment		0
Stock compensation expense	18,291	16,643	13,969
Amortization of debt discount, premium and issuance costs	7,895	12,358	7,404
Deferred income taxes	14,041	(709)	(3,484)
Changes in operating assets and liabilities, net of effects of business combinations:
Accounts receivable	0	0	0
Other current assets	(1,068)	(1,432)	(2,661)
Other assets	168	(2,978)	10,840
Accounts payable	1,450	330	560
Accrued expenses	(25,396)	(1,287)	(1,508)
Net cash provided by operating activities	26,072	(2,848)	27,629
Investing activities
Business combinations, net of cash acquired	0	(406,305)	0
Purchases of property and equipment	(30,413)	(15,262)	(10,890)
Investment in businesses	0	0	0
Proceeds from sale of equity investment		0	0
Proceeds from sale of assets and businesses	45,788	63,418	0
Net cash used in investing activities	15,375	(358,149)	(10,890)
Financing activities
Borrowings on revolving facilities	970,000	575,000	1,115,000
Payments on revolving facilities	(960,000)	(650,000)	(880,000)
Proceeds from term loans	1,139,487	600,127	0
Payments on term loans	(1,156,377)	(230,524)	(26,884)
Revolving facility debt issuance costs	(4,392)
Borrowings of other debt	25,630	11,935	8,684
Principal payments on other debt	(13,748)	(15,144)	(11,923)
Dividends paid to Holdings	(4,753)	(2,929)	(28,956)
Equity investment by Holdings	2,017	1,672	1,649
Intercompany	(40,410)	67,115	(199,024)
Tax benefit from stock based awards			1,846
Increase (decrease) in overdrafts	(9,899)	10,746	6,869
Proceeds from issuance of non-controlling interests	0	0	0
Purchase of non-controlling interests	0	0	0
Distributions to non-controlling interests	0	0	0
Net cash provided by (used in) financing activities	(52,445)	367,998	(12,739)
Net increase in cash and cash equivalents	(10,998)	7,001	4,000
Cash and cash equivalents at beginning of period	11,071	4,070	70
Cash and cash equivalents at end of period	73	11,071	4,070
Subsidiary Guarantors | Reportable legal entities
Operating activities
Net income	146,964	105,943	138,812
Adjustments to reconcile net income to net cash provided by operating activities:
Distributions from unconsolidated subsidiaries	19,940	20,380	13,870
Depreciation and amortization	76,268	67,932	56,957
Provision for bad debts	44,080	41,737	40,708
Equity in earnings of unconsolidated subsidiaries	(20,973)	(19,838)	(16,719)
Equity in earnings of consolidated subsidiaries	(13,588)	8,061	(7,527)
Loss on extinguishment of debt	0	0
Loss (gain) on sale of assets and businesses	(4,828)	(12,975)	(1,128)
Gain on sale of equity investment		(2,779)	(29,647)
Impairment of equity investment		5,339
Stock compensation expense	0	0	0
Amortization of debt discount, premium and issuance costs	0	0	0
Deferred income taxes	(40,788)	0	0
Changes in operating assets and liabilities, net of effects of business combinations:
Accounts receivable	(126,451)	15,768	(83,142)
Other current assets	4,411	10,310	(2,236)
Other assets	(4,235)	51,586	(6,415)
Accounts payable	2,534	(24,877)	8,569
Accrued expenses	2,168	53,764	9,569
Net cash provided by operating activities	85,502	320,351	121,671
Investing activities
Business combinations, net of cash acquired	(10,006)	(59,520)	0
Purchases of property and equipment	(136,075)	(101,564)	(134,002)
Investment in businesses	(12,682)	(4,723)	(2,347)
Proceeds from sale of equity investment		3,779	33,096
Proceeds from sale of assets and businesses	15,022	16,978	1,742
Net cash used in investing activities	(143,741)	(145,050)	(101,511)
Financing activities
Borrowings on revolving facilities	0	0	0
Payments on revolving facilities	0	0	0
Proceeds from term loans	0	0	0
Payments on term loans	0	0	0
Revolving facility debt issuance costs	0
Borrowings of other debt	0	0	0
Principal payments on other debt	(456)	(751)	(2,736)
Dividends paid to Holdings	0	0	0
Equity investment by Holdings	0	0	0
Intercompany	57,204	(169,473)	(15,930)
Tax benefit from stock based awards			0
Increase (decrease) in overdrafts	0	0	0
Proceeds from issuance of non-controlling interests	0	0	0
Purchase of non-controlling interests	(120)	(2,099)	0
Distributions to non-controlling interests	0	(217)	(242)
Net cash provided by (used in) financing activities	56,628	(172,540)	(18,908)
Net increase in cash and cash equivalents	(1,611)	2,761	1,252
Cash and cash equivalents at beginning of period	6,467	3,706	2,454
Cash and cash equivalents at end of period	4,856	6,467	3,706
Non-Guarantor Subsidiaries | Reportable legal entities
Operating activities
Net income	20,971	(10,239)	16,499
Adjustments to reconcile net income to net cash provided by operating activities:
Distributions from unconsolidated subsidiaries	66	96	99
Depreciation and amortization	14,258	11,314	10,088
Provision for bad debts	14,534	9,206	9,073
Equity in earnings of unconsolidated subsidiaries	(81)	(105)	(92)
Equity in earnings of consolidated subsidiaries	0	0	0
Loss on extinguishment of debt	0	0
Loss (gain) on sale of assets and businesses	(4,602)	246	16
Gain on sale of equity investment		0	0
Impairment of equity investment		0
Stock compensation expense	0	0	0
Amortization of debt discount, premium and issuance costs	0	0	0
Deferred income taxes	156	0	0
Changes in operating assets and liabilities, net of effects of business combinations:
Accounts receivable	(43,043)	(40,080)	(10,255)
Other current assets	(3,697)	(4,619)	(396)
Other assets	3,413	(53,295)	288
Accounts payable	828	5,979	2,654
Accrued expenses	13,244	(2,091)	5,696
Net cash provided by operating activities	16,047	(83,588)	33,670
Investing activities
Business combinations, net of cash acquired	(1,664)	(953)	(8,832)
Purchases of property and equipment	(37,843)	(28,861)	(10,979)
Investment in businesses	0	0	0
Proceeds from sale of equity investment		0	0
Proceeds from sale of assets and businesses	19,537	67	24
Net cash used in investing activities	(19,970)	(29,747)	(19,787)
Financing activities
Borrowings on revolving facilities	0	0	0
Payments on revolving facilities	0	0	0
Proceeds from term loans	0	0	0
Payments on term loans	0	0	0
Revolving facility debt issuance costs	0
Borrowings of other debt	18,224	12,970	1,681
Principal payments on other debt	(3,036)	(2,554)	(1,513)
Dividends paid to Holdings	0	0	0
Equity investment by Holdings	0	0	0
Intercompany	(16,794)	102,358	(2,981)
Tax benefit from stock based awards			0
Increase (decrease) in overdrafts	0	0	0
Proceeds from issuance of non-controlling interests	9,982	11,846	0
Purchase of non-controlling interests	0	0	(1,095)
Distributions to non-controlling interests	(4,948)	(6,854)	(10,180)
Net cash provided by (used in) financing activities	3,428	117,766	(14,088)
Net increase in cash and cash equivalents	(495)	4,431	(205)
Cash and cash equivalents at beginning of period	5,056	625	830
Cash and cash equivalents at end of period	4,561	5,056	625
Non-Guarantor Concentra | Reportable legal entities
Operating activities
Net income	68,735	19,661	(10,005)
Adjustments to reconcile net income to net cash provided by operating activities:
Distributions from unconsolidated subsidiaries	0	0	0
Depreciation and amortization	61,945	60,717	33,644
Provision for bad debts	20,877	18,150	9,591
Equity in earnings of unconsolidated subsidiaries	0	0	0
Equity in earnings of consolidated subsidiaries	0	0	0
Loss on extinguishment of debt	0	10,853
Loss (gain) on sale of assets and businesses	20	(21)	14
Gain on sale of equity investment		0	0
Impairment of equity investment		0
Stock compensation expense	993	770	1,016
Amortization of debt discount, premium and issuance costs	3,235	3,298	2,139
Deferred income taxes	(45,733)	(11,882)	1,426
Changes in operating assets and liabilities, net of effects of business combinations:
Accounts receivable	(27,697)	(15,008)	825
Other current assets	1,951	13,191	2,790
Other assets	(232)	13,977	0
Accounts payable	(909)	3,076	(9,438)
Accrued expenses	27,325	(4,094)	(6,557)
Net cash provided by operating activities	110,510	112,688	25,445
Investing activities
Business combinations, net of cash acquired	(15,720)	(5,428)	(1,052,796)
Purchases of property and equipment	(28,912)	(15,946)	(26,771)
Investment in businesses	0	0	0
Proceeds from sale of equity investment		0	0
Proceeds from sale of assets and businesses	3	0	1
Net cash used in investing activities	(44,629)	(21,374)	(1,079,566)
Financing activities
Borrowings on revolving facilities	0	0	20,000
Payments on revolving facilities	0	(5,000)	(15,000)
Proceeds from term loans	0	195,217	623,575
Payments on term loans	(23,065)	(207,510)	(2,250)
Revolving facility debt issuance costs	0
Borrowings of other debt	2,767	2,816	3,009
Principal payments on other debt	(3,407)	(2,952)	(1,964)
Dividends paid to Holdings	0	0	0
Equity investment by Holdings	0	0	0
Intercompany	0	0	217,935
Tax benefit from stock based awards			0
Increase (decrease) in overdrafts	0	0	0
Proceeds from issuance of non-controlling interests	0	0	217,065
Purchase of non-controlling interests	0	0	0
Distributions to non-controlling interests	(5,552)	(3,484)	(2,215)
Net cash provided by (used in) financing activities	(29,257)	(20,913)	1,060,155
Net increase in cash and cash equivalents	36,624	70,401	6,034
Cash and cash equivalents at beginning of period	76,435	6,034	0
Cash and cash equivalents at end of period	113,059	76,435	6,034
Select
Operating activities
Net income	220,645	125,270	135,996
Adjustments to reconcile net income to net cash provided by operating activities:
Distributions from unconsolidated subsidiaries	20,006	20,476	13,969
Depreciation and amortization	160,011	145,311	104,981
Provision for bad debts	79,491	69,093	59,372
Equity in earnings of unconsolidated subsidiaries	(21,054)	(19,943)	(16,811)
Equity in earnings of consolidated subsidiaries	0	0	0
Loss on extinguishment of debt	6,527	11,626	0
Loss (gain) on sale of assets and businesses	(10,349)	(46,488)	(1,098)
Gain on sale of equity investment	0	(2,779)	(29,647)
Impairment of equity investment	0	5,339	0
Stock compensation expense	19,284	17,413	14,985
Amortization of debt discount, premium and issuance costs	11,130	15,656	9,543
Deferred income taxes	(72,324)	(12,591)	(2,058)
Changes in operating assets and liabilities, net of effects of business combinations:
Accounts receivable	(197,191)	(39,320)	(92,572)
Other current assets	1,597	17,450	(2,503)
Other assets	(886)	9,290	4,713
Accounts payable	3,903	(15,492)	2,345
Accrued expenses	17,341	46,292	7,200
Net cash provided by operating activities	238,131	346,603	208,415
Investing activities
Business combinations, net of cash acquired	(27,390)	(472,206)	(1,061,628)
Purchases of property and equipment	(233,243)	(161,633)	(182,642)
Investment in businesses	(12,682)	(4,723)	(2,347)
Proceeds from sale of equity investment	0	3,779	33,096
Proceeds from sale of assets and businesses	80,350	80,463	1,767
Net cash used in investing activities	(192,965)	(554,320)	(1,211,754)
Financing activities
Borrowings on revolving facilities	970,000	575,000	1,135,000
Payments on revolving facilities	(960,000)	(655,000)	(895,000)
Proceeds from term loans	1,139,487	795,344	623,575
Payments on term loans	(1,179,442)	(438,034)	(29,134)
Revolving facility debt issuance costs	(4,392)	0	0
Borrowings of other debt	46,621	27,721	13,374
Principal payments on other debt	(20,647)	(21,401)	(18,136)
Dividends paid to Holdings	(4,753)	(2,929)	(28,956)
Equity investment by Holdings	2,017	1,672	1,649
Intercompany	0	0	0
Tax benefit from stock based awards	0	0	1,846
Increase (decrease) in overdrafts	(9,899)	10,746	6,869
Proceeds from issuance of non-controlling interests	9,982	11,846	217,065
Purchase of non-controlling interests	(120)	(2,099)	(1,095)
Distributions to non-controlling interests	(10,500)	(10,555)	(12,637)
Net cash provided by (used in) financing activities	(21,646)	292,311	1,014,420
Net increase in cash and cash equivalents	23,520	84,594	11,081
Cash and cash equivalents at beginning of period	99,029	14,435	3,354
Cash and cash equivalents at end of period	$ 122,549	$ 99,029	$ 14,435