Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2011

Stockholders' Equity

Components of basic and diluted earnings per share

	Three months ended			Nine months ended
	September 30,			September 30,
	2011		2010	2011	2010
	(in thousands, except per share amounts)
Net income	$	39,834	40,533	135,437	110,594
Weighted average shares outstanding - basic	85,776		85,438	85,951	85,683
Dilutive potential shares from stock options	6		10	13	32
Weighted average shares outstanding - diluted	85,782		85,448	85,964	85,715
Earnings per share:
Basic	$	0.46	0.47	1.58	1.29
Diluted	$	0.46	0.47	1.58	1.29