Revenue - Schedule of U.K. Revenue Attributed to Each Category (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 777,251	$ 760,916	$ 2,327,230	$ 2,268,895
U.K. Facilities [Member]
Disaggregation of Revenue [Line Items]
Revenue	267,868	272,290	820,074	836,394
U.K. Facilities [Member] \| Health Care Facilities [Member]
Disaggregation of Revenue [Line Items]
Revenue	148,138	150,589	455,399	464,098
U.K. Facilities [Member] \| Education and Children's Services [Member]
Disaggregation of Revenue [Line Items]
Revenue	43,388	45,795	135,652	141,945
U.K. Facilities [Member] \| Adult Care Facilities [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 76,342	$ 75,906	$ 229,023	$ 230,351

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration