Computation of Basic and Diluted (Loss) Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net (loss) income		$ (47,156)	$ 485,397	$ 475,547
Less: Dividends paid on and (loss)/earnings allocated to participating securities		(3,357)	(3,425)	(3,008)
(Loss) earnings applicable to common stock		$ (50,513)	$ 481,972	$ 472,539
Weighted average common shares outstanding		448,982,223	440,988,102	439,251,238
Basic (loss) earnings per common share		$ (0.11)	$ 1.09	$ 1.08
Potential dilutive common shares	[1]	0	0	0
Total shares for diluted (loss) earnings per share computation		448,982,223	440,988,102	439,251,238
Diluted (loss) earnings per common share and common share equivalents		$ (0.11)	$ 1.09	$ 1.08

[1] Options to purchase 58,560 shares and 60,300 shares, respectively, of the Company's common stock that were outstanding as of December 31, 2014 and 2013, at respective weighted average exercise prices of $18.04 and $17.99, were excluded from the respective computations of diluted EPS because their inclusion would have had an antidilutive effect.