Note 4. Investment Securities: Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block] (Details) (USD $) | 9 Months Ended | 12 Months Ended |
In Thousands, unless otherwise specified | Sep. 30, 2013 | Dec. 31, 2012 |
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value | $320,853 | $130,045 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | 13,119 | 1,683 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 34,752 | 22,199 |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss | 1,979 | 814 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 355,605 | 152,244 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 15,098 | 2,497 |
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year | 109 | 45 |
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year | 16 | 23 |
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | 125 | 68 |
Domestic Corporate Debt Securities | ' | ' |
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value | 142,526 | 61,386 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | 6,169 | 953 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 4,684 | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss | 344 | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 147,210 | 61,386 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 6,513 | 953 |
Commercial Mortgage Backed Securities | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 572 | 570 |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss | 403 | 405 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 572 | 570 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 403 | 405 |
US Treasury Securities | ' | ' |
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value | 4,127 | 5,667 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | 71 | 2 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 4,127 | 5,667 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 71 | 2 |
US Government-sponsored Enterprises Debt Securities | ' | ' |
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value | 3,574 | 6,162 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | 91 | 40 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 5,482 | 2,784 |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss | 208 | 27 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 9,056 | 8,946 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 299 | 67 |
US States and Political Subdivisions Debt Securities | ' | ' |
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value | 139,702 | 53,036 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | 4,801 | 657 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 22,687 | 17,707 |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss | 898 | 338 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 162,389 | 70,743 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 5,699 | 995 |
Foreign Government Debt | ' | ' |
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value | 26,215 | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | 1,684 | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 1,327 | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss | 126 | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 27,542 | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 1,810 | ' |
Redeemable Preferred Stock | ' | ' |
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value | 3,471 | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | 292 | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 3,471 | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 292 | ' |
Debt Securities | ' | ' |
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value | 319,615 | 128,667 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | 13,108 | 1,673 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 34,752 | 22,199 |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss | 1,979 | 814 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 354,367 | 150,866 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 15,087 | 2,487 |
Nonredeemable Preferred Stock | ' | ' |
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value | 1,238 | 1,378 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | 11 | 10 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 1,238 | 1,378 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 11 | 10 |
Residential Mortgage Backed Securities Member | ' | ' |
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value | ' | 2,416 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | ' | 21 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | ' | 1,138 |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss | ' | 44 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | ' | 3,554 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | ' | $65 |