Goodwill and Other Intangible Assets - Additional Information (Detail)	6 Months Ended
Jun. 30, 2018 Community Country
U.S. Operating Segment
Goodwill [Line Items]
Number of reporting unit \| Community	19
International Operating Segment
Goodwill [Line Items]
Number of reporting unit \| Country	7

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_GoodwillLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration