Summary Of Accounting Policies (Components Of Acquired Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Mar. 31, 2011
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 337,800	$ 423,327
Accumulated Amortization	(254,481)	(303,451)
Net Carrying Amount	83,319	119,876
Customer-Related Intangibles [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	305,103	378,412
Accumulated Amortization	(242,111)	(283,732)
Net Carrying Amount	62,992	94,680
Licenses And Other Intangibles [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	32,697	44,915
Accumulated Amortization	(12,370)	(19,719)
Net Carrying Amount	$ 20,327	$ 25,196