Earnings Per Share - Reconciliation of Net Income (Loss) and Number of Common Shares Used in Computations of "Basic" EPS and "Diluted" EPS (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Net income (loss)	$ 36,095	$ (53,897)
Plus: Income attributable to non-controlling interests	(305)	(256)
Less: Preferred dividends	(8,383)	(8,383)
Less: Earnings attributable to unvested shares and operating partnership units	(172)	(203)
Net income (loss) attributable to common shareholders after allocation to participating securities	$ 27,235	$ (62,739)
Denominators – Number of Shares
Basic—Average shares outstanding	180,546	184,560
Assumed conversion of diluted securities	545	0
Diluted—Average shares outstanding	181,091	184,560
Earnings (Loss) Per Share:
Basic	$ 0.15	$ (0.34)
Diluted	$ 0.15	$ (0.34)