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Investment Securities (Details 3) (USD $) In Thousands, unless otherwise specified | Dec. 31, 2013 | Dec. 31, 2012
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Available for sale: |  |
Fair value, less than 12 months | $ 2,534,354 | $ 743,609
Unrealized losses, less than 12 months | (101,585) | (5,590)
Fair value, 12 months or more | 434,554 | 43,353
Unrealized losses, 12 months or more | (31,534) | (12,254)
Fair value, total | 2,968,908 | 786,962
Unrealized losses, total | (133,119) | (17,844)
Residential mortgage-backed securities |  |
Available for sale: |  |
Fair value, less than 12 months | 2,459,565 | 738,492
Unrealized losses, less than 12 months | (98,022) | (5,476)
Fair value, 12 months or more | 420,262 | 32,860
Unrealized losses, 12 months or more | (26,552) | (10,557)
Fair value, total | 2,879,827 | 771,352
Unrealized losses, total | (124,574) | (16,033)
Obligations of states and political subdivisions |  |
Available for sale: |  |
Fair value, less than 12 months | 55,327 | 5,117
Unrealized losses, less than 12 months | (3,025) | (114)
Fair value, 12 months or more | 14,292 | 10,437
Unrealized losses, 12 months or more | (4,982) | (1,677)
Fair value, total | 69,619 | 15,554
Unrealized losses, total | (8,007) | (1,791)
Equity Securities |  |
Available for sale: |  |
Fair value, less than 12 months | 19,462 |
Unrealized losses, less than 12 months | (538) |
Fair value, 12 months or more |  | 56
Unrealized losses, 12 months or more |  | (20)
Fair value, total | 19,462 | 56
Unrealized losses, total | $ (538) | $ (20)

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