Supplemental Cash Flow Information (Tables)

12 Months Ended

Dec. 31, 2011

Supplemental Cash Flow Information [Abstract]

Schedule Of Supplemental Cash Flow Information

	For the years ended December 31,
(in thousands)	2011			2010
Supplemental disclosure of non-cash transactions:
Employee share-based compensation	$	14,242		$	11,176
Unrealized losses on available for sale securities		(11	)		—
Supplemental disclosure of cash flow information:
Cash paid for income taxes	$	93,648		$	52,484
Cash paid for interest		4,141			4,100
Cash received for stock option exercises		14,242			3,342
Cash received for employee stock purchase plan		482			377