Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2016

Earnings Per Share (Tables) [Abstract]

Computation of basic and diluted earnings per share

		Year Ended December 31,
		2016		2015		2014
Numerator for basic and diluted earnings per share -
	net income attributable to common stockholders	$	1,012,397	$	818,344	$	446,745
Denominator for basic earnings per
	share: weighted-average shares		358,275		348,240		306,272
Effect of dilutive securities:
	Employee stock options		110		143		188
	Non-vested restricted shares		449		535		500
	Redeemable shares		1,393		310		-
	Convertible senior unsecured notes		-		196		787
Dilutive potential common shares			1,952		1,184		1,475
Denominator for diluted earnings per
	share: adjusted-weighted average shares		360,227		349,424		307,747
Basic earnings per share		$	2.83	$	2.35	$	1.46
Diluted earnings per share		$	2.81	$	2.34	$	1.45