Investments (Details)	3 Months Ended
Jun. 30, 2013
Investments (Textual) [Abstract]
Investment maturity date range end	Sep. 26, 2013

The latest maturity date when short-term debt instruments are reported on the Schedule of Investments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 12

-Footnote 2

Name:	invest_InvestmentMaturityDateRangeEnd1
Namespace Prefix:	invest_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration