Computation of Basic and Diluted Earnings (Loss) Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income available to common shareholders	$ 92,121	$ 89,370
Less: Dividends paid on and earnings allocated to participating securities	(1,170)	(1,119)
Earnings applicable to common stock	$ 90,951	$ 88,251
Weighted average common shares outstanding	464,993,970	465,493,702
Basic earnings per common share	$ 0.20	$ 0.19
Potential dilutive common shares	418,674
Total shares for diluted earnings per common share computation	465,412,644	465,493,702
Diluted earnings per common share and common share equivalents	$ 0.20	$ 0.19