Note 5 - Fair Value Measurements (Details Textual) - USD ($) $ in Millions  | 
Sep. 30, 2018  | 
Aug. 01, 2018  | 
Jul. 02, 2018  | 
Jun. 30, 2018  | 
|---|---|---|---|---|
| Business Combination, Liabilities Arising from Contingencies, Amount Recognized | $ 7.0 | |||
| Exosome Diagnostics, Inc [Member] | ||||
| Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High | 325.0 | $ 325.0 | ||
| Business Combination, Liabilities Arising from Contingencies, Amount Recognized | 1.8 | |||
| QT Holdings Corporation [Member] | ||||
| Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High | 51.0 | $ 51.0 | ||
| Business Combination, Liabilities Arising from Contingencies, Amount Recognized | 5.2 | |||
| CCXI [Member] | ||||
| Investments, Total | $ 18.8 | $ 18.8 | 
| X | ||||||||||
- Definition For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
- Definition The amount, measured at acquisition-date fair value, of all liabilities assumed that arise from contingencies and were recognized by the entity. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
- Definition Sum of the carrying amounts as of the balance sheet date of all investments. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
- Details 
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| X | ||||||||||
- Details 
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| X | ||||||||||
- Details 
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