CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Change in fair value of marketable securities, tax	$ 1,483	$ (482)	$ 2,975	$ (904)
Unrecognized actuarial gain (loss) on pension liability, tax	(179)	67	(295)	65
Change in fair value of cash flow hedges, tax	$ 2,952	$ 1,230	$ 1,681	$ (3,996)