Note 5. Investments: Schedule of Unrealized Loss on Investments (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 40,407	$ 41,416
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	200	499
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	9,341	8,168
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	423	376
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	49,748	49,584
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	$ 623	$ 875
Available For Sale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions Less Than 12 Months	14	36
Available For Sale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions More Than 12 Months	9	7
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	23	43
Corporate Debt Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 12,208	$ 24,627
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	90	387
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	7,933	6,760
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	346	296
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	20,141	31,387
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	436	683
US Treasury Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	25,002	995
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	6	4
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	25,002	995
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	6	4
US States and Political Subdivisions Debt Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	1,896	13,013
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	79	98
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1,408	1,408
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	77	80
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	3,304	14,421
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	156	178
Nonredeemable Preferred Stock
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	1,301	1,324
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	25	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,301	1,324
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	$ 25	3
Foreign Government Debt Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		484
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss		6
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		484
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		6
US Government-sponsored Enterprises Debt Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		973
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss		1
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		973
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		$ 1