Interest-bearing Deposits and Securities: Schedule of Held to Maturity Securities Amortized Cost and Fair Value by Contractual Maturity (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Due in one year or less
Held to Maturity Securities Amortized Cost by Contractual Maturity	$ 1,378	$ 2,707
Held to Maturity Securities Fair Value by Contractual Maturity	1,395	2,768
Due after one year through five years
Held to Maturity Securities Amortized Cost by Contractual Maturity	15,366	14,420
Held to Maturity Securities Fair Value by Contractual Maturity	16,118	15,150
Due after five years through ten years
Held to Maturity Securities Amortized Cost by Contractual Maturity	12,049	9,726
Held to Maturity Securities Fair Value by Contractual Maturity	12,555	10,254
Due after ten years through twenty years
Held to Maturity Securities Amortized Cost by Contractual Maturity	48,507	46,741
Held to Maturity Securities Fair Value by Contractual Maturity	52,935	49,936
Due after twenty years
Held to Maturity Securities Amortized Cost by Contractual Maturity	6,012	1,844
Held to Maturity Securities Fair Value by Contractual Maturity	6,150	1,999
Total by contractual maturity
Held to Maturity Securities Amortized Cost by Contractual Maturity	83,312	75,438
Held to Maturity Securities Fair Value by Contractual Maturity	$ 89,153	$ 80,107