Note 2. Investment Securities: Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value (Details) $ in Thousands	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	$ 210,357	$ 161,904
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	3,709	2,540
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	91,565	161,489
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	4,512	3,736
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	301,922	323,393
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 8,221	$ 6,276
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year	99	70
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	31	46
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	130	116
Corporate Debt Securities
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	$ 101,903	$ 77,868
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2,559	1,473
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	55,217	69,498
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	3,309	1,841
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	157,120	147,366
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	5,868	3,314
Residential Mortgage Backed Securities Member
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	2,867	2,062
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	14	16
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		1,562
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		6
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,867	3,624
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	14	22
US Treasury Securities
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	19,809
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	64
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	19,809
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	64
US Government-sponsored Enterprises Debt Securities
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	6,539
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	128
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	4,997	9,581
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	126	86
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	11,536	9,581
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	254	86
US States and Political Subdivisions Debt Securities
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	68,898	58,819
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	780	744
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	31,351	67,318
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	1,077	1,642
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	100,249	126,137
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	1,857	2,386
Foreign Government Debt
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	484	21,148
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	6	171
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		12,229
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		128
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	484	33,377
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	6	299
Redeemable Preferred Stock
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	3,749
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	14
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	3,749
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	14
Debt Securities
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	204,249	159,897
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	3,565	2,404
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	91,565	161,141
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	4,512	3,725
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	295,814	321,038
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	8,077	6,129
COMMON STOCK
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	4,784	2,007
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	142	136
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		348
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		11
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	4,784	2,355
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	142	147
Nonredeemable Preferred Stock
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	1,324
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,324
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	2
Equity Securities
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	6,108	2,007
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	144	136
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		348
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		11
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	6,108	2,355
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 144	147
Commercial Mortgage Backed Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		953
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		22
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		953
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		$ 22