Cash, Cash Equivalents and Marketable Securities - Summary of Cash, Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized Cost	$ 103,502	$ 181,726
Cash and cash equivalents, Unrealized Losses	(2)	(2)
Cash and cash equivalents, Estimated Fair Value	103,500	181,724
Marketable securities, Amortized Cost	228,251	173,459
Marketable securities, Unrealized Gains	2	5
Marketable securities, Unrealized Losses	(1,721)	(136)
Marketable securities, Estimated Fair Value	226,532	173,328
Cash
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized Cost	42,703	44,499
Cash and cash equivalents, Estimated Fair Value	42,703	44,499
Money Market Funds
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized Cost	25,506	117,023
Cash and cash equivalents, Estimated Fair Value	25,506	117,023
Commercial Paper
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized Cost	30,287	16,898
Cash and cash equivalents, Unrealized Losses	(2)	(1)
Cash and cash equivalents, Estimated Fair Value	30,285	16,897
Marketable securities, Amortized Cost	33,550	34,978
Marketable securities, Unrealized Gains	1
Marketable securities, Unrealized Losses	(27)	(10)
Marketable securities, Estimated Fair Value	33,524	34,968
U.S. Government and Agency Securities
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized Cost	5,006
Cash and cash equivalents, Estimated Fair Value	5,006
Marketable securities, Amortized Cost	128,214	85,309
Marketable securities, Unrealized Gains	1	1
Marketable securities, Unrealized Losses	(1,001)	(88)
Marketable securities, Estimated Fair Value	127,214	85,222
Corporate Debt Securities
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized Cost		3,306
Cash and cash equivalents, Unrealized Losses		(1)
Cash and cash equivalents, Estimated Fair Value		3,305
Marketable securities, Amortized Cost	66,487	53,172
Marketable securities, Unrealized Gains		4
Marketable securities, Unrealized Losses	(693)	(38)
Marketable securities, Estimated Fair Value	$ 65,794	$ 53,138

This item represents the cash and cash equivalents at an amortized cost basis.

No definition available.

Name:	kdny_CashAndCashEquivalentsAmortizedCost
Namespace Prefix:	kdny_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Cash and cash equivalents gross unrealized losses.

+ References

No definition available.

+ Details

Name:	kdny_CashAndCashEquivalentsGrossUnrealizedLosses
Namespace Prefix:	kdny_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

+ Details

Name:	us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26610-111562

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

No definition available.

+ Details

Name:	us-gaap_CashAndCashEquivalentsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_CashAndCashEquivalentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_CashMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: