Mortgage-backed Securities: Schedule of held-to-maturity mortgage-backed securities, Contractual Maturities (Details) (Collateralized Mortgage Backed Securities, USD $) In Thousands, unless otherwise specified	Sep. 30, 2012
Collateralized Mortgage Backed Securities
Held-to-maturity Securities, Debt Maturities, after One Through Five Years, Net Carrying Amount	$ 3
Held-to-maturity Securities, Debt Maturities, Year Two Through Five, Fair Value	3
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	43
Held-to-maturity Securities, Debt Maturities, Year Six Through Ten, Fair Value	46
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount	118
Held-to-maturity Securities, Debt Maturities, after Ten Years, Fair Value	121
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount	164
Held-to-maturity Securities, Debt Maturities, Fair Value	$ 170