Discount on the revenue participation liability, resulting from a derivative instrument.

No definition available.

Name:	chrs_DiscountOnRevenueParticipationLiabilityFromDerivativeInstrument
Namespace Prefix:	chrs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Interest expense, inclusive of the amortization of discount and issuance costs.

+ References

No definition available.

+ Details

Name:	chrs_InterestExpenseInclusiveOfAmortizationOfDiscountAndIssuanceCostsOnRevenueParticipationLiability
Namespace Prefix:	chrs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Issuance costs on the revenue participation liability.

+ References

No definition available.

+ Details

Name:	chrs_IssuanceCostsOnRevenueParticipationLiability
Namespace Prefix:	chrs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow to buy out the right to receive future payments in accordance with agreement entered into by the company.

+ References

No definition available.

+ Details

Name:	chrs_PaymentsToBuyOutRightToReceiveFuturePayments
Namespace Prefix:	chrs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Revenue Purchase and Sale Agreement purchase price.

+ References

No definition available.

+ Details

Name:	chrs_RevenuePurchaseAndSaleAgreementCertainConditionsPurchasePriceMultiplier
Namespace Prefix:	chrs_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Revenue Purchase and Sale Agreement purchase price.

+ References

No definition available.

+ Details

Name:	chrs_RevenuePurchaseAndSaleAgreementPurchasePrice
Namespace Prefix:	chrs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The percent to be received pertaining to the sales of the companies products and services.

+ References

No definition available.

+ Details

Name:	chrs_RevenuePurchaseAndSaleAgreementRightToReceivePercent
Namespace Prefix:	chrs_
Data Type:	dtr-types:percentItemType
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_EmbeddedDerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=chrs_RevenuePurchaseAndSaleAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=chrs_UdenycaBusinessMember
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_IncomeStatementLocationAxis=us-gaap_InterestExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=chrs_UdenycaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=chrs_UdenycaAndLoqtorziMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Financial Liabilities - Revenue Purchase and Sale Agreement - Narrative (Details) - Revenue Purchase and Sale Agreement - USD ($) $ in Millions		3 Months Ended
	Apr. 15, 2025	Mar. 31, 2025	May 08, 2024
Embedded Derivative [Line Items]
Revenue Purchase and Sale Agreement, Purchase price			$ 37.5
Purchase price multiplier			2.25
Discount on revenue participation liability from allocation of purchase price to the embedded derivative		$ 9.2
Issuance costs on revenue participation liability		1.4
UDENYCA \| Subsequent Event
Embedded Derivative [Line Items]
Payments to buy out right to receive future payments	$ 47.7
Interest expense
Embedded Derivative [Line Items]
Interest expense, inclusive of the amortization of discount and issuance costs		2.6
Interest expense \| UDENYCA
Embedded Derivative [Line Items]
Interest expense, inclusive of the amortization of discount and issuance costs		$ 1.7
UDENYCA
Embedded Derivative [Line Items]
Revenue payment, Percentage of U.S. net sales			5.00%
UDENYCA and LOQTORZI
Embedded Derivative [Line Items]
Revenue payment, Percentage of U.S. net sales			0.50%