Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2012

Earnings Per Share [Abstract]

Summary Of Earnings Per Share, Basic And Diluted

	Three Months Ended March 31,
	2012		2011
Net income	$	42,079	$	32,335
Denominator for basic and diluted earnings per share:
Weighted-average shares outstanding		81,702		78,575
Share-based payment awards classified as participating securities		863		1,362
Denominator for basic earnings per share		82,565		79,937
Dilutive securities		2,599		3,441
Denominator for diluted earnings per share		85,164		83,378
Basic earnings per share	$	0.51	$	0.40
Diluted earnings per share	$	0.49	$	0.39