Company Earnings Per Share - Schedule of Computation of Basic and Diluted Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Line Items]
Income from continuing operations									$ 80,793	$ 238,183	$ 81,122
Noncontrolling interests - consolidated real estate entities										(22,554)	(107)
Noncontrolling interests - Operating Partnership									(170)	(509)	(279)
Dividends to preferred shareholders	$ (922)	$ (922)	$ (922)	$ (922)	$ (922)	$ (922)	$ (922)	$ (922)	(3,688)	(3,688)	(3,688)
Unvested restricted stock (allocation of earnings)									(182)	(481)	(170)
Income from continuing operations available to common shareholders, adjusted									$ 76,753	$ 210,951	$ 76,955
Weighted average shares outstanding - basic									54,290	54,262	54,336
Dilutive shares from stock options									16	91	172
Weighted average shares outstanding - diluted									54,306	54,353	54,508
Basic									$ 1.41	$ 3.89	$ 1.42
Diluted									$ 1.41	$ 3.88	$ 1.41
Continuing Operations [Member]
Earnings Per Share [Line Items]
Noncontrolling interests - Operating Partnership											$ (202)