Segment Information (Reconciliation Of Total Segment Profit To The Company's Income Before Income Taxes) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2013		Dec. 31, 2012
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Company’s total segment profit	$ 188,521		$ 111,707		$ 332,784		$ 268,710
Less:
Shared services and corporate expenses	(45,207)	[1]	(27,349)	[1]	(126,761)	[1]	(86,137)	[1]
Depreciation and amortization	(1,530)		(2,020)		(4,766)		(6,240)
Operating income	141,784		82,338		201,257		176,333
Interest expense	(15,574)		(22,774)		(52,560)		(73,549)
Interest and other income	1,771		1,079		4,750		3,058
Loss on extinguishment of debt	0		(14,652)		(36,653)		(23,811)
Equity interests income (loss)	(1,321)		(3,512)		13,158		(1,902)
Income before income taxes	$ 126,660		$ 42,479		$ 129,952		$ 80,129

[1] The following table presents general and administrative expenses for shared services and corporate expenses not allocated to segment general and administrative expenses: Three Months Ended Nine Months Ended December 31, December 31, 2013 2012 2013 2012 (Amounts in thousands)Share-based compensation expense$12,064 $8,997 $52,199 $25,645Severance and transaction costs related to the acquisition of Summit— — — 2,027Other shared services and corporate expenses33,143 18,352 74,562 58,465 $45,207 $27,349 $126,761 $86,137