Note 3. Investment Securities: Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	$ 106,072	$ 335,792
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	1,562	14,937
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	211,224	63,529
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	6,765	5,132
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	317,296	399,321
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	8,327	20,069
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year	49	126
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	67	27
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	116	153
Domestic Corporate Debt Securities
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	37,147	124,531
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	572	5,340
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	78,183	21,070
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	2,707	2,127
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	115,330	145,601
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	3,279	7,467
Residential Mortgage Backed Securities Member
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	1,770	2,047
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	6	8
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,770	2,047
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	6	8
Commercial Mortgage Backed Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	906	593
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	69	382
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	906	593
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	69	382
US Government-sponsored Enterprises Debt Securities
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	13,395	22,731
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	133	123
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	5,614	5,360
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	126	217
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	19,009	28,091
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	259	340
US States and Political Subdivisions Debt Securities
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	34,752	149,704
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	482	7,312
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	102,168	32,983
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	2,560	2,065
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	136,920	182,687
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	3,042	9,377
Foreign Government Debt
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	16,608	27,587
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	293	1,766
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	24,353	3,523
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	1,303	341
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	40,961	31,110
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	1,596	2,107
Debt Securities
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	103,672	330,578
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	1,486	14,833
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	211,224	63,529
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	6,765	5,132
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	314,896	394,107
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	8,251	19,965
COMMON STOCK
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	2,400	2,589
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	76	70
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,400	2,589
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	76	70
Equity Securities
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value	2,400	5,214
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	76	104
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,400	5,214
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	76	104
US Treasury Securities
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value		493
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		493
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		6
Redeemable Preferred Stock
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value		3,485
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss		278
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		3,485
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		278
Nonredeemable Preferred Stock
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value		2,625
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss		34
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		2,625
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		$ 34