Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2012

Earnings Per Share [Abstract]

Schedule Of Net Income Attributable To Common Stockholders

	Year Ended December 31,
	2012			2011			2010
Net income	$	385,555		$	258,966		$	221,393
Less:
Net income attributable to participating securities	(2,160		)	(2,310		)	(2,230		)
Net income attributable to common shareholders	$	383,395		$	256,656		$	219,163

Reconciliation Of Denominator For Basic And Diluted Earnings (Loss) Per Share

The following table reconciles the denominator for the basic and diluted earnings per share computations shown in the consolidated statements of operations:

	Year Ended December 31,
	2012		2011		2010
Weighted average common shares—basic	66,289,429		65,927,421		65,472,875
Plus incremental shares from:
Assumed exercise of options	352,066		372,737		203,789
Weighted average common shares—diluted	66,641,495		66,300,158		65,676,664
Earnings per share:
Basic	$	5.78	$	3.89	$	3.35
Diluted	$	5.75	$	3.87	$	3.34