Investments: Schedule of Unrealized Loss on Investments (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	5	4
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 999	$ 1,018
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(5)	(2)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	999	1,018
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Losses	(5)	(2)
US Government Agencies Debt Securities
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	3
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	746
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(4)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	746
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Losses	(4)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	2	4
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	253	1,018
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(1)	(2)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	253	1,018
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Losses	$ (1)	$ (2)