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		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income (loss)	$ 23,901	$ (8,692)	$ 77,533	$ (65,222)
Plus: Income attributable to non-controlling interests	(271)	(239)	(836)	(1,191)
Less: Preferred dividends	(8,382)	(8,382)	(25,148)	(25,148)
Less: Earnings attributable to unvested shares and operating partnership units	(174)	(119)	(520)	(971)
Net income (loss) attributable to common shareholders after allocation to participating securities	$ 15,074	$ (17,432)	$ 51,029	$ (92,532)
Denominators – Number of Shares
Basic—Average shares outstanding	180,567	184,655	180,555	184,616
Assumed conversion of diluted securities	940	0	1,064	0
Diluted—Average shares outstanding	181,507	184,655	181,619	184,616
Earnings (Loss) Per Share:
Basic	$ 0.08	$ (0.09)	$ 0.28	$ (0.50)
Diluted	$ 0.08	$ (0.09)	$ 0.28	$ (0.50)