Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2011

Stockholders' Equity

Components of basic and diluted earnings per share

	2011		2010		2009
	(in thousands, except per share amounts)
Net income	$	175,459		156,959		105,505
Weighted average shares outstanding — basic		85,783		85,618		85,484
Dilutive potential shares from stock options		10		29		60
Weighted average shares outstanding — diluted		85,793		85,647		85,544
Earnings per share:
Basic	$	2.05		1.83		1.23
Diluted	$	2.05		1.83		1.23