Business - Additional Information (Detail)	5 Months Ended	7 Months Ended	12 Months Ended
Dec. 31, 2014 Segment	Jul. 31, 2014 Segment	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Percentage of limited partnership interest in Operating Partnership			100.00%
Number of operating segments	1us-gaap_NumberOfOperatingSegments	3us-gaap_NumberOfOperatingSegments
Number of reportable segments	1us-gaap_NumberOfReportableSegments	3us-gaap_NumberOfReportableSegments

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

No definition available.

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