Financial Instruments And Investments (Unrealized Holding Losses Included In Pre-Tax Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011
Financial Instruments And Investments [Abstract]
Gross unrealized holding losses included In pre-tax income	$ 0	$ 0	$ (2,116)	$ (263)