Interest-bearing Deposits and Securities: Schedule of Held to Maturity Securities Age Analysis of Unrealized Losses and Fair Value (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
Securities-held-to-maturity, fair value	6,733	7,886
Municipal bonds tax exempt
Securities-held-to-maturity, fair value	81,170	70,973
Held to Maturity Securities Gross Unrealized Losses	(39)
Total municipal bonds
Securities-held-to-maturity, fair value	87,903	78,859
Held to Maturity Securities Gross Unrealized Losses	(39)
Corporate bonds
Securities-held-to-maturity, fair value	1,250	1,248
Held to Maturity Securities Gross Unrealized Losses		(2)
Less Than 12 Months | Municipal bonds tax exempt
Securities-held-to-maturity, fair value	6,195
Held to Maturity Securities Gross Unrealized Losses	(39)
Less Than 12 Months | Total municipal bonds
Securities-held-to-maturity, fair value	6,195
Held to Maturity Securities Gross Unrealized Losses	(39)
Less Than 12 Months | Total held to maturity securities age analysis
Securities-held-to-maturity, fair value	6,195
Held to Maturity Securities Gross Unrealized Losses	(39)
12 Months or More | Corporate bonds
Securities-held-to-maturity, fair value		498
Held to Maturity Securities Gross Unrealized Losses		(2)
12 Months or More | Total held to maturity securities age analysis
Securities-held-to-maturity, fair value		498
Held to Maturity Securities Gross Unrealized Losses		(2)
Total Securities Aging | Municipal bonds tax exempt
Securities-held-to-maturity, fair value	6,195
Held to Maturity Securities Gross Unrealized Losses	(39)
Total Securities Aging | Total municipal bonds
Securities-held-to-maturity, fair value	6,195
Held to Maturity Securities Gross Unrealized Losses	(39)
Total Securities Aging | Corporate bonds
Securities-held-to-maturity, fair value		498
Held to Maturity Securities Gross Unrealized Losses		(2)
Total Securities Aging | Total held to maturity securities age analysis
Securities-held-to-maturity, fair value	6,195	498
Held to Maturity Securities Gross Unrealized Losses	$ (39)	$ (2)