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

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-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.19)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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Stockholders' Equity and Noncontrolling Interests - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions			1 Months Ended	3 Months Ended		6 Months Ended
	Nov. 12, 2014	Feb. 12, 2013	Dec. 31, 2014	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Class of Stock [Line Items]
Income attributable to noncontrolling interests				$ 2,537	$ 4,433	$ 5,011	$ 6,857
6.875 Series C Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Number of depositary shares sold		5.6
Depository shares to cumulative redeemable preferred stock ratio		1.00%
Percentage of redeemable preferred stock		6.875%
Cash proceeds from sale depositary shares		$ 135,200
Dividend payment accrual date		Feb. 12, 2018
Cumulative redeemable preferred stock liquidation preference (in usd per share)		$ 25.00
Annual dividend on depositary shares (in usd per share)		$ 1.71875
Series C Preferred Stock
Class of Stock [Line Items]
Number of depositary shares sold	1.6
Percentage of redeemable preferred stock		6.875%
Cash proceeds from sale depositary shares	$ 39,300
Series A Preferred Stock
Class of Stock [Line Items]
Dividend rate on preferred stock			8.00%