Property and Equipment - Additional Information (Detail) - USD ($)	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Property Plant And Equipment [Abstract]
Depreciation and amortization expense	$ 8,000	$ 11,000
Assets under capital leases	$ 0		$ 0

The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production; or to reflect the nonrecurring reduction in book value of an impaired long-lived physical asset.

No definition available.

Name:	gidyl_DepreciationAndAmortizationExpenseImpairedAsset
Namespace Prefix:	gidyl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration