Summary Of Accounting Policies (Schedule Of Components Of Acquired Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Mar. 31, 2011
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 299,421	$ 423,327
Accumulated Amortization	(230,167)	(303,451)
Net Carrying Amount	69,254	119,876
Customer-Related Intangibles [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	276,681	378,412
Accumulated Amortization	(221,238)	(283,732)
Net Carrying Amount	55,443	94,680
Licenses And Other Intangibles [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	22,740	44,915
Accumulated Amortization	(8,929)	(19,719)
Net Carrying Amount	$ 13,811	$ 25,196