Business and Organization (Detail)	6 Months Ended	12 Months Ended
Jun. 30, 2017 Segment	Dec. 31, 2016 Acquisition
Organization And Description Of Business [Line Items]
Number of reportable segments \| Segment	2
Acquisitions 2016
Organization And Description Of Business [Line Items]
Number of business acquisitions \| Acquisition		5

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

No definition available.

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration