Summary Of Accounting Policies (Components Of Acquired Intangible Assets) (Details) (USD $) In Thousands	Sep. 30, 2011	Mar. 31, 2011
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 347,425	$ 423,327
Accumulated Amortization	(255,462)	(303,451)
Net Carrying Amount	91,963	119,876
Customer-Related Intangibles [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	309,113	378,412
Accumulated Amortization	(237,273)	(283,732)
Net Carrying Amount	71,840	94,680
Licenses And Other Intangibles [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	38,312	44,915
Accumulated Amortization	(18,189)	(19,719)
Net Carrying Amount	$ 20,123	$ 25,196