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Marketable Securities (Details 3) $ in Thousands | Jan. 31, 2018 USD ($)
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Available-for-sale securities: |
Unrealized Losses | $ 14
Fair Value | 2,158
Federal Government Sponsored Enterprise notes [Member] |
Available-for-sale securities: |
Unrealized Losses | 13
Fair Value | 1,810
Municipal Bonds [Member] |
Available-for-sale securities: |
Unrealized Losses | 1
Fair Value | $ 348

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