Investments (Details Textual) (USD $)	Jun. 30, 2012	Sep. 30, 2011
Investments (Textual) [Abstract]
Amortized cost of held-to-maturity debt securities	$ 0	$ 3,000,000
Fair market value of held-to-maturity debt securities	$ 42,320,000	$ 3,100,000

This item represents the total of all debt securities grouped by maturity dates, at fair value, which are categorized as held-to-maturity.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27232-111563

Name:	us-gaap_HeldToMaturitySecuritiesDebtMaturitiesFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant