Description of Business and Significant Accounting Policies - Additional Paid In Capital (Provident Shares Held In Escrow) (Details) - USD ($)	1 Months Ended	12 Months Ended				13 Months Ended
	Sep. 30, 2010	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2012	Sep. 30, 2011
US Government Securities and Other Securities - Deposits and Receivables		$ 471,738,813	$ 502,483,279
Business Combination, Consideration Transferred		$ 45,000,000
Provident Group Asset Acquisition [Member]
Business Combination, Consideration Transferred					$ 5,000,000
Business Combination, Cost of Acquired Entity, Equity Interest Issued or Issuable, Total Shares Purchased and Placed In Escrow						214,325
Business Combination, Cost of Acquired Entity, Equity Interest Issued or Issuable, Period From Date of Closing Over Which Shares Will be Released from Escrow	5 years
Stock Redeemed or Called During Period, Shares			204,271
Business Combination, Cost of Acquired Entity, Equity Interest Issued or Issuable, Shares Released from Escrow			0	10,054