Redeemable Non-Controlling Interest (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Changes in Carrying Amount (Fair Value) of Redeemable Non-Controlling Interests [Roll Forward]
Beginning balance	$ 133,943
Ending balance	137,750	$ 133,943
Carrying Amount (Fair Value) of Redeemable Non-Controlling Interest [Abstract]
Redeemable non-controlling interests	133,943	133,943	$ 137,750	$ 133,943
Redeemable Non-Controlling Interest [Member]
Changes in Carrying Amount (Fair Value) of Redeemable Non-Controlling Interests [Roll Forward]
Beginning balance	133,943	102,572
Operating results allocated to redeemable non-controlling interest partners	10,659	8,433
Distributions to redeemable non-controlling interest partners	(10,221)	(9,835)
Changes in the fair value of redeemable non-controlling interest	11,893	24,770
Purchases of redeemable non-controlling interest	(8,934)	8,145
Acquired interest	6,230	0
Sales of redeemable non-controlling interest - temporary equity	3,120	0
Reduction of non-controlling interest due to sale of USPh partnership interest	(6,132)	0
Notes receivable related to sales of redeemable non-controlling interest - temporary equity	(2,870)	(142)
Other	62	0
Ending balance	137,750	133,943
Carrying Amount (Fair Value) of Redeemable Non-Controlling Interest [Abstract]
Contractual time period has lapsed but holder's employment has not been terminated			51,921	42,624
Contractual time period has not lapsed and holder's employment has not been terminated			85,829	91,319
Holder's employment has terminated and contractual time period has expired			0	0
Holder's employment has terminated and contractual time period has not expired			0	0
Redeemable non-controlling interests	$ 137,750	$ 102,572	$ 137,750	$ 133,943
Therapy Practice [Member] | Minimum [Member]
Business Combination, Description [Abstract]
Business acquisition, percentage of limited partnership acquired			50.00%
Therapy Practice [Member] | Maximum [Member]
Business Combination, Description [Abstract]
Business acquisition, percentage of limited partnership acquired			90.00%
Therapy Practice [Member] | NewCo. [Member]
Business Combination, Description [Abstract]
Percentage of equity interest of subsidiary contributed for acquisition			100.00%
Business acquisition, percentage of general partnership interest acquired			100.00%
Business acquisition, consideration payable, term of note	2 years
Employment agreement renewal term	1 year
Non-Compete agreement term under condition of termination of employment of employed selling shareholder	2 years
Therapy Practice [Member] | NewCo. [Member] | Minimum [Member]
Business Combination, Description [Abstract]
Employment agreement term	3 years
Non-Compete agreement term regardless of whether the selling shareholder is employed	5 years
Therapy Practice [Member] | NewCo. [Member] | Maximum [Member]
Business Combination, Description [Abstract]
Employment agreement term	5 years
Non-Compete agreement term regardless of whether the selling shareholder is employed	6 years