Investment in Unconsolidated Ventures - Additional Information (Detail) $ in Thousands	9 Months Ended
Sep. 30, 2015 USD ($) Venture	Sep. 30, 2014 USD ($)
Schedule of Equity Method Investments [Line Items]
Investment in unconsolidated ventures	$ 23,908	$ 5,016
Distributions of return on investments and earnings	$ 15,126	$ 4,418
Equity Method Investments [Member]
Schedule of Equity Method Investments [Line Items]
Number of ventures under ownership interest using equity method \| Venture	20

The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3213-108585

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