Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2014

Earnings Per Share (Tables) [Abstract]

Computation of basic and diluted earnings per share

		Year Ended December 31,
		2014		2013		2012
Numerator for basic and diluted earnings
	per share - net income attributable to
	common stockholders	$	446,745	$	78,714	$	221,884
Denominator for basic earnings per
	share: weighted-average shares		306,272		276,929		224,343
Effect of dilutive securities:
	Employee stock options		188		226		231
	Non-vested restricted shares		500		457		312
	Convertible senior unsecured notes		787		1,149		1,067
Dilutive potential common shares			1,475		1,832		1,610
Denominator for diluted earnings per
	share: adjusted-weighted average shares		307,747		278,761		225,953
Basic earnings per share		$	1.46	$	0.28	$	0.99
Diluted earnings per share		$	1.45	$	0.28	$	0.98