MBS And Other Investments: Schedule of significant inputs utilized to measure management's estimate of the credit loss component on OTTI securities (Details)	Jun. 30, 2013	Sep. 30, 2012
Minimum
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
OTTI significant inputs - Constant prepayment rate	6.00%	6.00%
OTTI significant inputs - Collateral default rate	0.19%	0.06%
OTTI significant inputs - Loss severity rate	2.48%	0.52%
Maximum
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
OTTI significant inputs - Constant prepayment rate	15.00%	15.00%
OTTI significant inputs - Collateral default rate	23.90%	28.40%
OTTI significant inputs - Loss severity rate	73.69%	76.03%
Weighted Average
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
OTTI significant inputs - Constant prepayment rate	10.00%	8.77%
OTTI significant inputs - Collateral default rate	7.26%	8.74%
OTTI significant inputs - Loss severity rate	47.63%	48.28%