Calculation of Income (Loss) Per Share From Continuing and Discontinued Operations (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
BASIC EPS:
Income from continuing operations	$ 188,009	$ 299,477	$ 322,780
Adjust for income attributed to holders of non-vested restricted stock	(1,859)	(2,532)	(2,545)
Income from continuing operations attributed to common stockholders	186,150	296,945	320,235
Loss from discontinued operations, net			(367)
Adjust for loss attributed to holders of non-vested restricted stock			3
Loss from discontinued operations attributed to common stockholders			(364)
Weighted average number of common shares outstanding, excluding non-vested shares of restricted stock	144,356	151,144	153,871
Basic income from continuing operations per common share	$ 1.29	$ 1.96	$ 2.08
Basic loss from discontinued operations per common share	$ 0.00	$ 0.00	$ 0.00
Basic net income per common share	$ 1.29	$ 1.96	$ 2.08
DILUTED EPS:
Income from continuing operations attributed to common stockholders	$ 186,150	$ 296,945	$ 320,235
Weighted average number of common shares outstanding, excluding non-vested shares of restricted stock	144,356	151,144	153,871
Add dilutive effect of potential common shares	947	555	1,433
Weighted average number of diluted common shares outstanding	145,303	151,699	155,304
Diluted income from continuing operations per common share	$ 1.28	$ 1.96	$ 2.06
Diluted loss from discontinued operations per common share	$ 0.00	$ 0.00	$ 0.00
Diluted net income per common share	$ 1.28	$ 1.96	$ 2.06
Potentially dilutive securities excluded as anti-dilutive	2,447	5,416	1,641