Summary Of Accounting Policies (Estimated Future Annual Amortization Expense For Acquired Intangible Assets) (Details) (USD $) In Thousands	6 Months Ended
	Sep. 30, 2011
Summary Of Accounting Policies [Abstract]
2012	$ 19,167	[1]
2013	31,109
2014	20,811
2015	10,911
2016	5,701
Thereafter	4,264
Total amortization expense	$ 91,963

[1] Represents estimated amortization for the six-month period ending March 31, 2012.