Revenue - Schedule of U.S. Revenue and Percentage Generated by Each Payor Type (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Revenue	$ 782,810	$ 760,617
U.S. Facilities [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Revenue	$ 509,217	$ 487,960
Revenue, Percentage	100.00%	100.00%
U.S. Facilities [Member] | Commercial [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Revenue	$ 143,142	$ 139,427
Revenue, Percentage	28.10%	28.60%
U.S. Facilities [Member] | Medicare [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Revenue	$ 72,271	$ 72,616
Revenue, Percentage	14.20%	14.90%
U.S. Facilities [Member] | Medicaid [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Revenue	$ 260,044	$ 239,191
Revenue, Percentage	51.10%	49.00%
U.S. Facilities [Member] | Self-Pay [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Revenue	$ 27,034	$ 31,732
Revenue, Percentage	5.30%	6.50%
U.S. Facilities [Member] | Other [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Revenue	$ 6,726	$ 4,994
Revenue, Percentage	1.30%	1.00%