Purchase price of single share of a company.

No definition available.

Name:	ardx_SharePurchasePrice
Namespace Prefix:	ardx_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the per share amount of underwriting discounts and commissions.

+ References

No definition available.

+ Details

Name:	ardx_UnderwritingDiscountsAndCommissionsPerShare
Namespace Prefix:	ardx_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

+ Details

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

- Definition

The cash inflow from the additional capital contribution to the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585

+ Details

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

- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

Name:	us-gaap_SharePrice
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_CommonStockIssuanceMay2018OfferingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Shareholders Equity (Details) - USD ($) $ / shares in Units, $ in Millions	Jun. 25, 2018	May 25, 2018	Jun. 30, 2019	Dec. 31, 2018
Subsidiary, Sale of Stock [Line Items]
Common stock issued			62,800,869	62,516,627
Common stock, par value			$ 0.0001	$ 0.0001
Net proceeds	$ 53.8
Offering
Subsidiary, Sale of Stock [Line Items]
Common stock issued		12,500,000
Public offering price		$ 4.00
Underwriting discounts and commissions per share		0.24
Underwriters' option
Subsidiary, Sale of Stock [Line Items]
Common stock issued	1,875,000
Public offering price	$ 4.00
Underwriting discounts and commissions per share	0.24
Purchase price	$ 3.76	$ 3.76