Segment Information - Additional Information (Details)	6 Months Ended	9 Months Ended
Jun. 30, 2018 Region segment	Sep. 30, 2018 segment
Segment Reporting [Abstract]
Number of geographic regions \| Region	4
Number of reportable segments \| segment	4	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