Summary of Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill, Beginning Balance		$ 3,844,628	$ 3,825,157
Goodwill acquired during the period		5,926	45,090
Goodwill divested during the period			(2,135)
Adjustments to goodwill	[1]	19,206	(23,484)
Goodwill, Ending Balance		3,869,760	3,844,628
Acute Care Services
Goodwill [Line Items]
Goodwill, Beginning Balance		442,462	441,511
Goodwill acquired during the period		5,926	917
Adjustments to goodwill	[1]	27	34
Goodwill, Ending Balance		448,415	442,462
Behavioral Health Services
Goodwill [Line Items]
Goodwill, Beginning Balance		3,402,166	3,383,646
Goodwill acquired during the period			44,173
Goodwill divested during the period			(2,135)
Adjustments to goodwill	[1]	19,179	(23,518)
Goodwill, Ending Balance		$ 3,421,345	$ 3,402,166

[1] The increase/(decrease) in the Behavioral Health Services’ goodwill consists primarily of foreign currency translation adjustments.