Debt 1 (Details)	6 Months Ended	12 Months Ended
Sep. 30, 2013 Revolving Credit Facility due June 2018 [Member]	Mar. 31, 2013 Revolving Credit Facility due August 2016 [Member]
Rates applicable to revolving credit facility
Applicable margin on Base Rate borrowing	0.125%	0.25%
Weighted average interest rate on outstanding borrowings	0.00%	0.00%
Applicable margin on Eurocurrency Rate borrowing	1.00%	1.10%
Facility commitment fee	0.125%	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