Other Charges, Net (Details) (USD $)	12 Months Ended				1 Months Ended		12 Months Ended
	Mar. 31, 2011	Mar. 31, 2010	Mar. 31, 2009	Mar. 31, 2009 1% Convertible Subordinated Notes [Member]	Dec. 31, 2010 6.25% Senior Subordinated Notes [Member]	Jun. 30, 2009 6.25% Senior Subordinated Notes [Member]	Mar. 31, 2011 6.25% Senior Subordinated Notes [Member]
Other recognized charges	$ 6,300,000						$ 6,300,000
Other charges, net	6,267,000	206,895,000	89,262,000
Loss on early redemption of senior subordinated notes					13,200,000	2,300,000	13,200,000
Loss recognized in connection with divestiture of certain international entities	11,700,000
Gain on sale of equity investments	18,600,000
Debt instrument interest percentage				1.00%			6.25%
Investment charges related to equity investments and notes receivable		199,400,000
Amount recognized in charges to written-down certain notes receivable			74,100,000
Other-than-temporary impairment of certain investment charges			37,500,000
Gain associated with partial extinguishment of convertible subordinated notes			$ 22,300,000