The aggregate consideration of the repurchase rights of equity-based payment instruments.

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of additional cost recognized for award under share-based payment arrangement from occurrence of event accelerating recognition of cost.

+ References

No definition available.

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No definition available.

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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-Publisher FASB
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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-Publisher FASB
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- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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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.

+ References

No definition available.

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Share-based compensation - Restricted shares (Details)	3 Months Ended		6 Months Ended
Share-based compensation - Restricted shares (Details)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) $ / shares shares	Jun. 30, 2018 USD ($)	Jun. 30, 2019 GBP (£)	Jun. 30, 2019 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures
Total share-based compensation expense	$ 905,000	$ 335,000	$ 1,181,000	$ 587,000
Restricted shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase rights aggregate consideration \| £					£ 1.00
Number of shares
Unvested restricted ordinary shares at beginning \| shares			83,947
Vested \| shares			(83,947)
Weighted Average Grant Date Fair Value
Weighted average grant date fair value unvested, Beginning Balance \| $ / shares			$ 1.93
Weighted average grant date fair value vested \| $ / shares			$ 1.93
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures
Incremental share based compensation expense	200,000		$ 200,000
Total share-based compensation expense	300,000	27,000	400,000	100,000
Restricted shares \| Employees and directors
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures
Unrecognized compensation cost						$ 0
Restricted shares \| Employee
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures
Fair value of employee restricted share awards vested	$ 600,000	$ 34,000	$ 700,000	$ 100,000