Repurchase Agreements (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Sep. 30, 2016
Disclosure of Repurchase Agreements [Abstract]
Repurchase Agreements, Description of Potential Risks	Securities are delivered to the party with whom each transaction is executed and the party agrees to resell the same securities to the Bank at the maturity of the agreement. The Bank retains the right to substitute similar or like securities throughout the terms of the agreements. The repurchase agreements and collateral are subject to valuation at current market levels and the Bank may ask for the return of excess collateral or be required to post additional collateral due to changes in the market values of these items. The Bank may also be required to post additional collateral as a result of principal payments received on the securities pledged.
Repurchase agreements	$ 200,000	$ 200,000
Weighted average rate of repurchase agreements	2.94%	2.94%

Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.