Goodwill and Intangibles- Summary of Changes in Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Finite And Infinite Lived Intangible Assets [Line Items]
Indefinite-lived assets, carrying amount	$ 112,085	$ 97,999
Definite-lived assets, gross carrying amount	15,024	14,975
Intangible assets, gross carrying amount	127,109	112,974
Definite-lived assets, accumulated amortization	(12,143)	(10,968)
Definite-lived assets, net carrying amount	2,881	4,007
Intangible assets, net carrying amount	114,966	102,006
Certificates of need/licenses
Finite And Infinite Lived Intangible Assets [Line Items]
Indefinite-lived assets, carrying amount	41,290	33,327
Trade names
Finite And Infinite Lived Intangible Assets [Line Items]
Indefinite-lived assets, carrying amount	70,795	64,672
Definite-lived assets, gross carrying amount	9,292	9,294
Definite-lived assets, accumulated amortization	(6,798)	(5,991)
Definite-lived assets, net carrying amount	$ 2,494	$ 3,303
Trade names | Minimum
Finite And Infinite Lived Intangible Assets [Line Items]
Estimated useful life	5 months	8 months
Trade names | Maximum
Finite And Infinite Lived Intangible Assets [Line Items]
Estimated useful life	9 years	9 years
Non-compete agreements
Finite And Infinite Lived Intangible Assets [Line Items]
Definite-lived assets, gross carrying amount	$ 5,732	$ 5,681
Definite-lived assets, accumulated amortization	(5,345)	(4,977)
Definite-lived assets, net carrying amount	$ 387	$ 704
Non-compete agreements | Minimum
Finite And Infinite Lived Intangible Assets [Line Items]
Estimated useful life	1 month	2 months
Non-compete agreements | Maximum
Finite And Infinite Lived Intangible Assets [Line Items]
Estimated useful life	3 years	3 years