Leases - Operating lease maturities - Supplemental Information (Details) $ in Millions	6 Months Ended
Jun. 30, 2020 USD ($)
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 0.5
Weighted average items:
Weighted average remaining lease term (in years), Operating leases	3 years 1 month 6 days
Weighted average remaining lease term (in years), Finance leases	1 year 10 months 24 days
Weighted average discount rate - operating leases	3.91%
Weighted average discount rate - finance leases	4.08%

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Weighted average discount rate for finance lease calculated at point in time.

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Weighted average remaining lease term for finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

+ References

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-Publisher FASB
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Weighted average discount rate for operating lease calculated at point in time.

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Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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-SubTopic 20
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