Fair value of financial instruments and investments - Available-for-sale securities (Details) - USD ($) $ in Thousands |
Dec. 31, 2019 |
Dec. 31, 2018 |
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Debt Securities, Available-for-sale [Line Items] | ||
Unrealized losses | $ (28) | $ (8) |
Fair Value | 95,990 | 16,223 |
Unrealized losses | 0 | (3) |
Fair Value | 0 | 10,087 |
Unrealized losses | (28) | (11) |
Fair Value | 95,990 | 26,310 |
Commercial paper | ||
Debt Securities, Available-for-sale [Line Items] | ||
Unrealized losses | (1) | |
Fair Value | 1,993 | |
Unrealized losses | 0 | |
Fair Value | 0 | |
Unrealized losses | (1) | |
Fair Value | 1,993 | |
Corporate debt securities | ||
Debt Securities, Available-for-sale [Line Items] | ||
Unrealized losses | (20) | (7) |
Fair Value | 71,779 | 14,230 |
Unrealized losses | 0 | (3) |
Fair Value | 0 | 10,087 |
Unrealized losses | (20) | (10) |
Fair Value | 71,779 | $ 24,317 |
Asset-backed Securities | ||
Debt Securities, Available-for-sale [Line Items] | ||
Unrealized losses | (8) | |
Fair Value | 24,211 | |
Unrealized losses | 0 | |
Fair Value | 0 | |
Unrealized losses | (8) | |
Fair Value | $ 24,211 |
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- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position without allowance for credit loss. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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