Long-Term Debt Other Senior Notes and Senior Subordinated Notes (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,194,055	$ 1,203,035
Payments of debt issuance costs	7,372	8,820	3,722
Repayments of long-term debt	352,436	403,497	256,093
12 3/4% Senior Subordinated Notes Due 2012 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate			12.75%
9 5/8% Senior Notes Due 2011 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate			9.625%
7 3/4% Senior Notes Due 2013 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate			7.75%
8.5% Senior Notes, Due 2012 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate			8.50%
Subordinated Debt [Member]
Debt Instrument [Line Items]
Long-term debt, gross	619,016	621,189
Subordinated Debt [Member] | 8.5% Senior Notes, Due 2012 [Member]
Debt Instrument [Line Items]
Debt instrument, repurchase amount		23,635
Debt instrument, interest rate	8.50%
Amortization of debt discount (premium)		282
Long-term debt, gross	0	6,000
Payments of debt issuance costs		650
Repayments of long-term debt	$ 6,000