NET INCOME PER COMMON SHARE - Basic and Diluted Net Income Per Common Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Numerator for basic net income per common share: [Abstract]
Net income	$ 38,391	$ 34,918
Preferred share dividends	(3,238)	(5,270)
Unvested stock award participation in earnings	(24)	(32)
Numerator for basic net income per common share	35,129	29,616
Denominator for basic net income per common share: [Abstract]
Weighted average common shares outstanding (in shares)	95,777	95,560
Average unvested stock awards outstanding (in shares)	(428)	(540)
Denominator for basic net income per common share (in shares)	95,349	95,020
Basic net income per common share (in dollars per share)	$ 0.37	$ 0.31
Numerator for diluted net income per common share: [Abstract]
Net income available to common stockholders	35,129	29,616
Dividends on dilutive convertible preferred shares	0	75
Numerator for diluted net income per common share	$ 35,129	$ 29,691
Denominator for diluted net income per common share: [Abstract]
Basic weighted average common shares outstanding (in shares)	95,349	95,020
Net effect of dilutive equity awards	189	121
Net effect of dilutive convertible preferred shares (in shares)	0	309
Denominator for diluted net income per common share (in shares)	95,538	95,450
Diluted net income per common share (in dollars per share)	$ 0.37	$ 0.31