Condensed Consolidated Statements of Changes in Equity and Income (unaudited) - 6 months ended Jun. 30, 2018 - USD ($) $ in Thousands	Total	Select Medical Corporation	Common Stock	Common Stock Select Medical Corporation	Capital in Excess of Par	Capital in Excess of Par Select Medical Corporation	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit) Select Medical Corporation	Total Stockholders’ Equity	Total Stockholders’ Equity Select Medical Corporation	Non-controlling Interests	Non-controlling Interests Select Medical Corporation
Balance at Dec. 31, 2017	$ 640,818	$ 640,818
Redeemable Non-controlling Interests
Net income attributable to non-controlling interests	16,652	16,652
Issuance and exchange of non-controlling interests	163,659	163,659
Distributions to and purchases of non-controlling interests	(215,084)	(215,084)
Redemption adjustment on non-controlling interests	9,551	9,551
Other	636	636
Balance at Jun. 30, 2018	$ 616,232	$ 616,232
Balance (in shares) at Dec. 31, 2017	134,114,715	100	134,115,000	0
Balance at Dec. 31, 2017	$ 932,604	$ 932,604	$ 134	$ 0	$ 463,499	$ 947,370	$ 359,735	$ (124,002)	$ 823,368	$ 823,368	$ 109,236	$ 109,236
Increase (Decrease) in Stockholders' Equity
Net income	80,250	80,250					80,250	80,250	80,250	80,250
Net income attributable to non-controlling interests	7,639	7,639									7,639	7,639
Issuance of restricted stock (in shares)			174,000
Issuance of restricted stock	0		$ 0		0
Forfeitures of unvested restricted stock (in shares)			(88,000)
Forfeitures of unvested restricted stock	0		$ 0		0
Vesting of restricted stock	9,562				9,562				9,562
Repurchase of common shares (in shares)			(49,000)
Repurchase of common shares	(889)		$ 0		(490)		(399)		(889)
Exercise of stock options (in shares)			175,000
Exercise of stock options	1,620		$ 0		1,620				1,620
Additional investment by Holdings		1,620				1,620				1,620
Dividends declared and paid to Holdings		(889)						(889)		(889)
Contribution related to restricted stock award issuances by Holdings		9,562				9,562				9,562
Issuance and exchange of non-controlling interests	77,815	77,815			1,553	1,553	74,341	74,341	75,894	75,894	1,921	1,921
Distributions to and purchases of non-controlling interests	(87,601)	(87,601)			(932)	(932)	(83,617)	(83,617)	(84,549)	(84,549)	(3,052)	(3,052)
Redemption adjustment on non-controlling interests	(9,551)	(9,551)					(9,551)	(9,551)	(9,551)	(9,551)
Other	$ 478	$ 478					(234)	(234)	(234)	(234)	712	712
Balance (in shares) at Jun. 30, 2018	134,326,823	100	134,327,000	0
Balance at Jun. 30, 2018	$ 1,011,927	$ 1,011,927	$ 134	$ 0	$ 474,812	$ 959,173	$ 420,525	$ (63,702)	$ 895,471	$ 895,471	$ 116,456	$ 116,456