Represents the number of warrants or rights exercised during the period.

No definition available.

Name:	crdf_ClassOfWarrantOrRightNumberExercised
Namespace Prefix:	crdf_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow associated with the amount received from holders exercising their stock warrants.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromWarrantExercises
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=crdf_SeriesGWarrantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=crdf_SeriesFWarrantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Events (Details) - USD ($)		1 Months Ended	6 Months Ended
Subsequent Events (Details) - USD ($)	Aug. 11, 2020	Jul. 31, 2020	Jun. 30, 2020	Jun. 30, 2019	Aug. 06, 2020	Jun. 15, 2020
Subsequent Event [Line Items]
Proceeds from warrant exercise			$ 6,125,884	$ 3,283,830
Warrants exercised (in shares)			4,091,498
Exercise price of warrants (in USD per share)						$ 3.05
Series G Warrant \| Subsequent Event
Subsequent Event [Line Items]
Proceeds from warrant exercise		$ 2,300,000
Warrants exercised (in shares)		1,600,000
Exercise price of warrants (in USD per share)		$ 1.56
Series F Warrant \| Subsequent Event
Subsequent Event [Line Items]
Proceeds from warrant exercise	$ 600,000
Warrants exercised (in shares)	300,000
Exercise price of warrants (in USD per share)					$ 1.936