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Earnings Per Share of Common Stock - Additional Information (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Weighted average number of operating partnership units held by noncontrolling limited partners (in shares)	1,444,435	854,116	1,447,633	613,446

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- Definition

Weighted Average Number of Operating Partnership Units Held By Noncontrolling Interest

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No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

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No definition available.

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