Debt 3 (Details) (Revolving Credit Facility Due August 2016 [Member])	12 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Revolving Credit Facility Due August 2016 [Member]
Rates applicable to revolving credit facility
Applicable margin on Base Rate borrowing	0.25%	0.25%
Weighted average interest rate on outstanding borrowings	0.00%	0.00%
Applicable margin on Eurocurrency Rate borrowing	1.10%	1.10%
Facility commitment fee	0.15%	0.15%

Reflects the calculation as of the balance sheet date of the average interest rate weighted by the amount of long-term debt outstanding by type or by instrument at that time.

No definition available.

Name:	us-gaap_LongtermDebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant