Indebtedness (Senior Subordinated Notes Narrative) (Details) (7.125% Senior Subordinated Notes Maturing 2018 [Member], Senior Subordinated Notes [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
Mar. 31, 2013	Mar. 31, 2011
7.125% Senior Subordinated Notes Maturing 2018 [Member] \| Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Senior Subordinated Notes, Carrying Value	$ 215
Debt Instrument, Interest rate	7.125%
Debt Instrument, Maturity Date	Oct. 01, 2018
Debt Instrument, Interest Rate Terms	semi-annually on April 1 and October 1 of each year
Call feature description	The 2018 Senior Subordinated Notes have a redemption provision which permits the Company, at its option, to call the 2018 Notes at scheduled dates and prices
First scheduled optional redemption date	Oct. 01, 2013
Debt instrument call feature, cost in excess of principal percentage	103.563%
One-time interest penalty classified to interest expense		$ 2.6

Indebtedness (Senior Subordinated Notes Narrative) (Details) (7.125% Senior Subordinated Notes Maturing 2018 [Member], Senior Subordinated Notes [Member], USD $)
In Millions, unless otherwise specified

12 Months Ended

Mar. 31, 2013

Mar. 31, 2011

7.125% Senior Subordinated Notes Maturing 2018 [Member] | Senior Subordinated Notes [Member]

Debt Instrument [Line Items]

Senior Subordinated Notes, Carrying Value

$ 215

Debt Instrument, Interest rate

7.125%

Debt Instrument, Maturity Date

Oct. 01, 2018

Debt Instrument, Interest Rate Terms

semi-annually on April 1 and October 1 of each year

Call feature description

The 2018 Senior Subordinated Notes have a redemption provision which permits the Company, at its option, to call the 2018 Notes at scheduled dates and prices

First scheduled optional redemption date

Oct. 01, 2013

Debt instrument call feature, cost in excess of principal percentage

103.563%

One-time interest penalty classified to interest expense

$ 2.6

- Definition

Earliest date before maturity when the issuer can call the outstanding debt instrument for repayment or conversion to equity, in CCYY-MM-DD format.

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- Definition

Description of a feature that permits the issuer of the debt to repay or convert it before the stated maturity date (early retirement date). The description may include such items as the call price, the period that the issuer can call the debt, including the earliest call date, and other significant terms of the call feature, which may include the debt holders' ability to convert the debt to equity if the call option is exercised and contingent events that trigger the issuer's ability to call the debt.

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets.

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