Total number of common shares of an entity that have been offered, issued or sold to shareholders.

No definition available.

Name:	ardx_CommonStockSharesOfferedIssuedOrSold
Namespace Prefix:	ardx_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of maximum aggregate offering price.

+ References

No definition available.

+ Details

Name:	ardx_MaximumAggregateOfferingPrice
Namespace Prefix:	ardx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The period during which warrants can be exercised.

+ References

No definition available.

+ Details

Name:	ardx_WarrantTerm
Namespace Prefix:	ardx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of warrants (or share units) exercised during the current period.

+ References

No definition available.

+ Details

Name:	ardx_WarrantsExercisedInPeriod
Namespace Prefix:	ardx_
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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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

- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(2))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Per share or per unit amount of equity securities issued.

+ References

No definition available.

+ Details

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

- Definition

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.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=ardx_AtMarketOfferingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Stockholders' Equity (Details) - USD ($)	1 Months Ended	6 Months Ended
Stockholders' Equity (Details) - USD ($)	Jun. 30, 2015	Jun. 30, 2020	Sep. 30, 2020	Jul. 31, 2020
Subsidiary, Sale of Stock [Line Items]
Warrants sold and issued to purchase common stock	2,172,899
Purchase price of common shares	$ 0.125
Exercise price for warrants	$ 13.91
Warrant exercise period	5 years
Warrants exercised		0
Maximum aggregate offering price				$ 250,000,000
AT The Market Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares offered, issued or sold			0
Common Stock \| AT The Market Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Maximum aggregate offering price				$ 100,000,000