Goodwill And Intangible Assets (Changes To Goodwill) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011
Goodwill And Intangible Assets [Abstract]
Balance at beginning of period	$ 820,824	$ 810,285
Additions		10,900
Adjustments to purchase price allocations		3,932
Currency translation	5,893	(4,293)
Balance at end of period	$ 826,717	$ 820,824