Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2012

Earnings Per Share [Abstract]

Schedule Of Net Income Attributable To Common Stockholders

	Three Months Ended March 31,
	2012			2011
Net income	$	87,813		$	83,544
Less:
Net income attributable to participating securities		(610	)		(778	)
Net income attributable to common shareholders	$	87,203		$	82,766

Reconciliation Of Denominator For Basic And Diluted Earnings Per Share

	Three Months Ended March 31,
	2012		2011
Weighted average common shares—basic		66,109,297		65,745,555
Plus incremental shares from:
Assumed exercise of options		449,220		367,303
Weighted average common shares—diluted		66,558,517		66,112,858
Earnings per share:
Basic	$	1.32	$	1.26
Diluted	$	1.31	$	1.25