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		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Net income	$ 20,190	$ 156,435	$ 59,826	$ 218,679
Noncontrolling interests - consolidated real estate entities		(22,416)		(22,554)
Noncontrolling interests - Operating Partnership	(43)	(313)	(126)	(464)
Dividends to preferred shareholders	(922)	(922)	(2,766)	(2,766)
Unvested restricted stock (allocation of earnings)	(47)	(314)	(133)	(435)
Net income available to common shareholders, adjusted	$ 19,178	$ 132,470	$ 56,801	$ 192,460
Weighted average shares outstanding - basic	54,326	54,301	54,409	54,233
Dilutive shares from stock options	16	72	16	103
Weighted average shares outstanding - diluted	54,342	54,373	54,425	54,336
Basic	$ 0.35	$ 2.44	$ 1.04	$ 3.55
Diluted	$ 0.35	$ 2.44	$ 1.04	$ 3.54