Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2011

Earnings Per Share (Tables) [Abstract]

Computation of basic and diluted earnings per share

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2011		2010		2011		2010
Numerator for basic and diluted earnings per share — net income attributable to common stockholders	$	69,847	$	45,646	$	93,219	$	71,458
Denominator for basic earnings per share — weighted average shares		176,445		123,808		165,755		123,541
Effect of dilutive securities:
Employee stock options		178		102		184		104
Non-vested restricted shares		249		414		232		414
Convertible senior unsecured notes		616		—		287		—
Dilutive potential common shares		1,043		516		703		518
Denominator for diluted earnings per share — adjusted weighted average shares		177,488		124,324		166,458		124,059
Basic earnings per share	$	0.40	$	0.37	$	0.56	$	0.58
Diluted earnings per share	$	0.39	$	0.37	$	0.56	$	0.58