Fair Value Measurements - Additional Information (Detail) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
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| Fair Value Disclosures [Abstract] | |||
| Fair value of assets transfers in or out, level 1 to level 2 | $ 0 | $ 0 | $ 0 |
| Fair value of assets transfers in or out, level 2 to level 1 | 0 | 0 | 0 |
| Fair value, asset transfers into Level 3 | 0 | 0 | 0 |
| Fair value, asset transfers out of Level 3 | $ 0 | $ 0 | $ 0 |
| X | ||||||||||
- Definition Amount of transfers of assets measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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