Note 3 - Fair Value Measurement (Details Textual) - MidCap Agreement [Member] - MidCap Financial [Member] - USD ($) $ in Millions	Nov. 06, 2018	Sep. 25, 2018
Extinguishment of Debt, Amount	$ 32.3	$ 32.3
Debt Instrument, Prepayment and Exit Fees	$ 2.3	$ 2.3

The amount of prepayment and exit fees associated with a debt instrument.

No definition available.

Name:	oxfd_DebtInstrumentPrepaymentAndExitFees
Namespace Prefix:	oxfd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration