Interest-bearing Deposits and Securities: Schedule of Amortized Cost and Estimated Fair Value of Held to Maturity Securities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Securities-held-to-maturity, fair value	$ 89,153	$ 80,107
Municipal bonds taxable
Held to Maturity Securities Amortized Cost	6,292	7,496
Held to Maturity Securities Gross Unrealized Gains	441	390
Securities-held-to-maturity, fair value	6,733	7,886
Held to Maturity Securities Pecent of Total	7.60%	9.80%
Municipal bonds tax exempt
Held to Maturity Securities Amortized Cost	75,770	66,692
Held to Maturity Securities Gross Unrealized Gains	5,439	4,281
Held to Maturity Securities Gross Unrealized Losses	(39)
Securities-held-to-maturity, fair value	81,170	70,973
Held to Maturity Securities Pecent of Total	91.00%	88.60%
Total municipal bonds
Held to Maturity Securities Amortized Cost	82,062	74,188
Held to Maturity Securities Gross Unrealized Gains	5,880	4,671
Held to Maturity Securities Gross Unrealized Losses	(39)
Securities-held-to-maturity, fair value	87,903	78,859
Held to Maturity Securities Pecent of Total	98.60%	98.40%
Corporate bonds
Held to Maturity Securities Amortized Cost	1,250	1,250
Held to Maturity Securities Gross Unrealized Losses		(2)
Securities-held-to-maturity, fair value	1,250	1,248
Held to Maturity Securities Pecent of Total	1.40%	1.60%
Total held to maturity securities
Held to Maturity Securities Amortized Cost	83,312	75,438
Held to Maturity Securities Gross Unrealized Gains	5,880	4,671
Held to Maturity Securities Gross Unrealized Losses	(39)	(2)
Securities-held-to-maturity, fair value	$ 89,153	$ 80,107
Held to Maturity Securities Pecent of Total	100.00%	100.00%