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Investments with an Unrealized Loss Position (Details) (USD $) In Thousands, unless otherwise specified | Dec. 31, 2013 | Dec. 31, 2012
--- | --- | ---
Fair Value |  |
Fair Value, Less than 12 Months | $ 995,941 | $ 1,099,987
Fair Value, 12 Months or More | 77,856 | 67,438
Fair Value, Total | 1,073,797 | 1,167,425
Unrealized Loss |  |
Unrealized Loss, Less than 12 Months | (29,736) | (5,810)
Unrealized Loss, 12 Months or Longer | (6,177) | (640)
Unrealized Loss, Total | (35,913) | (6,450)
U.S. government sponsored enterprises |  |
Fair Value |  |
Fair Value, Less than 12 Months | 3 |
Fair Value, 12 Months or More | 0 |
Fair Value, Total | 3 |
Unrealized Loss |  |
Unrealized Loss, Less than 12 Months | 0 |
Unrealized Loss, 12 Months or Longer | 0 |
Unrealized Loss, Total | 0 |
State and local governments |  |
Fair Value |  |
Fair Value, Less than 12 Months | 408,812 | 102,896
Fair Value, 12 Months or More | 74,161 | 4,533
Fair Value, Total | 482,973 | 107,429
Unrealized Loss |  |
Unrealized Loss, Less than 12 Months | (17,838) | (1,531)
Unrealized Loss, 12 Months or Longer | (6,052) | (74)
Unrealized Loss, Total | (23,890) | (1,605)
Corporate bonds |  |
Fair Value |  |
Fair Value, Less than 12 Months | 129,515 | 41,856
Fair Value, 12 Months or More | 1,702 | 0
Fair Value, Total | 131,217 | 41,856
Unrealized Loss |  |
Unrealized Loss, Less than 12 Months | (1,672) | (238)
Unrealized Loss, 12 Months or Longer | (86) | 0
Unrealized Loss, Total | (1,758) | (238)
Residential mortgage-backed securities |  |
Fair Value |  |
Fair Value, Less than 12 Months | 457,611 | 955,235
Fair Value, 12 Months or More | 1,993 | 62,905
Fair Value, Total | 459,604 | 1,018,140
Unrealized Loss |  |
Unrealized Loss, Less than 12 Months | (10,226) | (4,041)
Unrealized Loss, 12 Months or Longer | (39) | (566)
Unrealized Loss, Total | $ (10,265) | $ (4,607)

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- Definition This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 + Details
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