Including the current and noncurrent portions, carrying value as of the balance sheet date of a written promise to pay a note, initially due after one year or beyond the operating cycle if longer, which can be exchanged for a specified amount of one or more securities (typically common stock), at the option of the issuer or the holder.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
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-Name Accounting Standards Codification
-Topic 946
-SubTopic 210
-Section S99
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-Publisher FASB
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-Topic 210
-SubTopic 10
-Section S99
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Name:	us-gaap_ConvertibleNotesPayable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Convertible Notes Payable - Schedule of Convertible Notes Payable (Detail) - USD ($) $ in Thousands	Apr. 03, 2020	Dec. 31, 2019	Nov. 30, 2019	Apr. 30, 2019
2018 Convertible Notes [Member]
Debt Instrument [Line Items]
Convertible notes, principal	$ 40,200	$ 40,250		$ 40,300
Accrued interest	2,800	2,319
Less: unamortized debt discount		(118)
Convertible notes, net		42,451
2019 Convertible Notes [Member]
Debt Instrument [Line Items]
Convertible notes, principal	29,300	29,332	$ 29,300
Accrued interest	$ 700	388
Less: unamortized debt discount		(55)
Convertible notes, net		$ 29,665