The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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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.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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The charge against earnings resulting from the aggregate write down of tangible assets from their carrying value to their fair value.

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Summary of Significant Accounting Policies - Property and Equipment (Details) - USD ($)		3 Months Ended	12 Months Ended
	Apr. 01, 2019	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Property, Plant and Equipment
Fixed asset impairment		$ 0	$ 4,102,000	$ 0	$ 0
Decrease in depreciation expense		$ (645,000)	$ (4,611,000)	$ (1,709,000)	$ (1,009,000)
Increase in basic and diluted net loss per ordinary share (usd per share)		$ (0.52)	$ (2.88)	$ (1.42)	$ (1.43)
Change in fixed asset assumptions
Property, Plant and Equipment
Decrease in depreciation expense			$ 300,000
Increase in basic and diluted net loss per ordinary share (usd per share)			$ 0.01
Office equipment
Property, Plant and Equipment
Property, plant and equipment useful life			3 years
Lab equipment \| Minimum
Property, Plant and Equipment
Property, plant and equipment useful life	5 years		5 years
Lab equipment \| Maximum
Property, Plant and Equipment
Property, plant and equipment useful life	10 years		10 years
Furniture and fixtures
Property, Plant and Equipment
Property, plant and equipment useful life			5 years