Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2010

Earnings Per Share (Tables) [Abstract]

Computation of basic and diluted earnings per share

	Year Ended December 31,
	2010		2009		2008
Numerator for basic and diluted earnings per share — net income attributable to common stockholders	$	106,882	$	171,190	$	260,098
Denominator for basic earnings per share — weighted average shares		127,656		114,207		93,732
Effect of dilutive securities:
Employee stock options		125		—		82
Non-vested restricted shares		420		405		443
Convertible senior unsecured notes		7		—		52
Dilutive potential common shares		552		405		577
Denominator for diluted earnings per share — adjusted weighted average shares		128,208		114,612		94,309
Basic earnings per share	$	0.84	$	1.50	$	2.77
Diluted earnings per share	$	0.83	$	1.49	$	2.76