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v3.20.1

INVESTMENTS (Details) - USD ($) $ in Thousands | Mar. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Available-for-sale |  |
Amortized Cost | $ 246,937 | $ 545,771
Gross Unrealized Holding Gains | 643 | 285
Gross Unrealized Holding Losses | 145 | 88
Fair Value | 247,435 | 545,968
Continuous Unrealized Loss Position less than 12 Months | 145 | 88
Short-term | Commercial paper |  |
Available-for-sale |  |
Amortized Cost | 57,107 | 83,478
Fair Value | 57,107 | 83,478
Short-term | Certificates of deposit |  |
Available-for-sale |  |
Amortized Cost |  | 28,049
Fair Value |  | 28,049
Short-term | Municipal securities |  |
Available-for-sale |  |
Amortized Cost | 95,819 | 147,983
Gross Unrealized Holding Gains | 114 | 145
Gross Unrealized Holding Losses | 113 | 20
Fair Value | 95,820 | 148,108
Continuous Unrealized Loss Position less than 12 Months | 113 | 20
Short-term | U.S. government agency securities |  |
Available-for-sale |  |
Amortized Cost | 21,441 | 40,620
Gross Unrealized Holding Gains | 62 | 5
Gross Unrealized Holding Losses |  | 35
Fair Value | 21,503 | 40,590
Continuous Unrealized Loss Position less than 12 Months |  | 35
Short-term | U.S. treasuries |  |
Available-for-sale |  |
Amortized Cost | 46,055 | 211,055
Gross Unrealized Holding Gains | 399 | 134
Gross Unrealized Holding Losses |  | 31
Fair Value | 46,454 | 211,158
Continuous Unrealized Loss Position less than 12 Months |  | 31
Short-term | Variable rate demand notes |  |
Available-for-sale |  |
Amortized Cost | 12,628 | 21,680
Fair Value | 12,628 | 21,680
Long-term | Municipal securities |  |
Available-for-sale |  |
Amortized Cost | 6,292 | 1,562
Gross Unrealized Holding Gains | 4 |
Gross Unrealized Holding Losses | 32 | 1
Fair Value | 6,264 | 1,561
Continuous Unrealized Loss Position less than 12 Months | 32 | 1
Long-term | U.S. government agency securities |  |
Available-for-sale |  |
Amortized Cost | 3,512 | 5,267
Gross Unrealized Holding Gains | 10 |
Gross Unrealized Holding Losses |  | 1
Fair Value | 3,522 | 5,266
Continuous Unrealized Loss Position less than 12 Months |  | 1
Long-term | U.S. treasuries |  |
Available-for-sale |  |
Amortized Cost | 4,083 | 6,077
Gross Unrealized Holding Gains | 54 | 1
Fair Value | $ 4,137 | $ 6,078

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