Amount of decrease in Additional-paid-in capital due to re-designation of ordinary shares to Series A Preferred shares.

No definition available.

Name:	exc_AdjustmentsToAdditionalPaidInCapitalReDesignationOfOrdinarySharesToSeriesPreferredShares
Namespace Prefix:	exc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

It represents the amount of non cash activities of series B convertible redeemable preferred shares in connection with equity-method investment.

+ References

No definition available.

+ Details

Name:	exc_NonCashActivitiesOfSeriesBConvertibleRedeemablePreferredSharesInConnectionWithEquityMethodInvestment
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of business days after the company received the deposits, within which the subscription amount is to be paid by the investors upon obtaining ODI approval.

+ References

No definition available.

+ Details

Name:	exc_NumberOfBusinessDaysAfterCompanyReceivedDepositsWithinWhichSubscriptionAmountIsToBePaidByInvestors
Namespace Prefix:	exc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of investors.

+ References

No definition available.

+ Details

Name:	exc_NumberOfInvestors
Namespace Prefix:	exc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of investors with whom share purchase agreements were entered into by the company.

+ References

No definition available.

+ Details

Name:	exc_NumberOfInvestorsWithWhomSharePurchaseAgreementsWereEntered
Namespace Prefix:	exc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflow for cost incurred directly with the issuance of temporary equity.

+ References

No definition available.

+ Details

Name:	exc_PaymentOfStockIssuanceCostsInRelationToTemporaryEquity
Namespace Prefix:	exc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow for refundable deposits in connection with temporary equity.

+ References

No definition available.

+ Details

Name:	exc_ProceedsFromRefundableDepositsInConnectionWithTemporaryEquity
Namespace Prefix:	exc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of shares reduced due to re-designation of ordinary shares to Series A Preferred shares.

+ References

No definition available.

+ Details

Name:	exc_SharesReDesignatedDuringPeriodShares
Namespace Prefix:	exc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the consideration for shares issuable.

+ References

No definition available.

+ Details

Name:	exc_TemporaryEquityConsiderationForSharesIssuable
Namespace Prefix:	exc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of excess of the preferred shares' fair value over the ordinary shares' fair value as share-based compensation expense.

+ References

No definition available.

+ Details

Name:	exc_TemporaryEquityExcessOfPreferredSharesFairValueOverOrdinarySharesFairValueShareBasedCompensationExpense
Namespace Prefix:	exc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the number of shares issuable.

+ References

No definition available.

+ Details

Name:	exc_TemporaryEquityNumberOfSharesIssuable
Namespace Prefix:	exc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of shares subscribed.

+ References

No definition available.

+ Details

Name:	exc_TemporaryEquityNumberOfSharesSubscribed
Namespace Prefix:	exc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage on outstanding shares for shares issued.

+ References

No definition available.

+ Details

Name:	exc_TemporaryEquitySharesIssuedPercentageOnOutstandingShares
Namespace Prefix:	exc_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of new stock classified as temporary equity issued during the period.

+ References

No definition available.

+ Details

Name:	exc_TemporaryEquityStockIssuedDuringPeriodSharesNewIssues
Namespace Prefix:	exc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The fair value of warrants.

+ References

No definition available.

+ Details

Name:	exc_WarrantLiabilitiesFairValue
Namespace Prefix:	exc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21475-112644

+ Details

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

- Definition

The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow from issuance of callable preferred stock which is identified as being convertible to another type of financial security at the option of the issuer or the holder.

+ 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 https://asc.fasb.org/extlink&oid=126954810&loc=d3e3255-108585

+ Details

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

- 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:	dtr-types: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_TemporaryEquityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate liquidation preference (or restrictions) of stock classified as temporary equity that has a preference in involuntary liquidation considerably in excess of the par or stated value of the shares. The liquidation preference is the difference between the preference in liquidation and the par or stated values of the share. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

+ References

No definition available.

+ Details

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

- Definition

Aggregate monetary value of a new issue of securities which have been allocated to investors to buy. When security is sold on a subscription basis, the issuer does not initially receive the total proceeds. In general, the issuer does not issue the security to the investor until it receives the entire proceeds. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

+ 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(27)(b))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Details

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- Details

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- Details

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- Details

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- Details

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Mezzanine equity - Information related to the Redeemable Convertible Preferred Shares (Details) ¥ / shares in Units, $ / shares in Units, ¥ in Thousands, $ in Thousands						1 Months Ended			2 Months Ended	3 Months Ended	5 Months Ended		12 Months Ended
	Jun. 29, 2021 CNY (¥)	Mar. 05, 2021 CNY (¥) ¥ / shares shares	Feb. 26, 2021 CNY (¥) shares	Jan. 16, 2020 CNY (¥) shares	Jan. 16, 2020 USD ($) $ / shares shares	Jul. 31, 2021 CNY (¥) shares	Jul. 31, 2021 USD ($) $ / shares shares	Jan. 31, 2020 CNY (¥) shares	Mar. 31, 2021 CNY (¥) shares	Jun. 30, 2021 USD ($) shares	Jul. 31, 2021 CNY (¥) D item shares	Jul. 31, 2021 USD ($) D item $ / shares shares	Dec. 31, 2022 CNY (¥) shares	Dec. 31, 2022 USD ($)	Dec. 31, 2021 CNY (¥) item shares	Dec. 31, 2021 USD ($) item shares	Dec. 31, 2020 CNY (¥) shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($)	May 17, 2021 shares	Mar. 31, 2021 USD ($) $ / shares shares	Mar. 05, 2021 $ / shares	Jan. 31, 2020 USD ($)
Mezzanine equity
Amount of excess of the ordinary shares' fair value over their par value															¥ 81,208
Cash contribution to acquire equity method investment													¥ 79,442	$ 11,518	1,345,637
Issuance of Series B Convertible Redeemable Preferred Shares in connection with acquisition of an equity-method investment															620,703
Series A Convertible Redeemable Preferred Shares
Mezzanine equity
Issuance of preferred shares (in shares) \| shares				26,841,535	26,841,535												26,841,535
Shares issued, price per share \| $ / shares					$ 6.71
Number of investors				2	2
Total consideration for shares issued															1,032,104		¥ 206,422
Issuance costs				¥ 8,500
Number of shares issuable \| shares					22,367,946
Amount of deposits received				¥ 1,032,104	$ 150,000			¥ 1,032,104
Number of shares subscribed \| shares				22,367,946	22,367,946			22,367,946
Consideration for shares issuable								¥ 206,422															$ 30,000
Re-designation of ordinary shares to Series A Preferred Shares, Shares(Note 19) \| shares			2,343,309
Amount of excess of the ordinary shares' fair value over their par value			¥ 81,208
Amount of excess of the preferred shares' fair value over the ordinary shares' fair value			¥ 16,452
Redeemable convertible preferred shares, liquidation preference													0		¥ 1,336,186
Series Angel Convertible Redeemable Preferred Shares
Mezzanine equity
Issuance of preferred shares (in shares) \| shares															6,016,207	6,016,207
Shares issued, price per share \| (per share)		¥ 13.62																				$ 2.11
Total consideration for shares issued	¥ 81,950														¥ 81,950
Number of shares issuable \| shares		6,016,207
Consideration for shares issuable		¥ 81,950
Shares issuable, percentage on outstanding shares		2.00%
Number of warrants to purchased shares exercised \| shares																				6,016,207
Redeemable convertible preferred shares, liquidation preference		¥ 273,519											0		¥ 273,519
Fair value of warrant liabilities		¥ 191,569
Series A+ Convertible Redeemable Preferred Shares
Mezzanine equity
Issuance of preferred shares (in shares) \| shares															29,361,157	29,361,157
Total consideration for shares issued				¥ 1,238,526	$ 180,000										¥ 1,331,641
Redeemable convertible preferred shares, liquidation preference													0		¥ 1,331,641
Series A+ Redeemable Convertible Preferred Shares
Mezzanine equity
Shares issued, price per share \| $ / shares																					$ 7.04
Issuance costs									¥ 10,000
Number of shares issuable \| shares									29,361,157												29,361,157
Consideration for shares issuable									¥ 1,331,641												$ 206,741
Series A++ Redeemable Convertible Preferred Shares
Mezzanine equity
Shares issued, price per share \| $ / shares							$ 8.31					$ 8.31
Number of investors \| item															4	4
Amount of deposits received											¥ 461,849	$ 71,000			¥ 461,849
Number of shares subscribed \| shares										8,546,916	8,546,916	8,546,916			8,546,916	8,546,916
Consideration for shares issuable										$ 71,000					¥ 452,241				$ 71,000
Number of investors with whom share purchase agreements were entered \| item											4	4
Number of business days after the company received the deposits, within which the subscription amount is to be paid by the investors \| D											5	5
Series B Convertible Redeemable Preferred Shares
Mezzanine equity
Issuance of preferred shares (in shares) \| shares						9,882,082	9,882,082								17,615,165	17,615,165
Shares issued, price per share \| $ / shares							$ 9.70					$ 9.70						$ 9.70
Total consideration for shares issued													¥ 159,485	$ 23,123	¥ 324,270	$ 50,000
Number of shares issuable \| shares													7,733,083					7,733,083
Consideration for shares issuable \| $																		$ 75,000
Cash contribution to acquire equity method investment \| $							$ 10,649
Redeemable convertible preferred shares, liquidation preference													¥ 0		1,104,188
Issuance of Series B Convertible Redeemable Preferred Shares in connection with acquisition of an equity-method investment						¥ 620,703	$ 95,800
Subscription receivable from Convertible Preferred Shares															¥ 159,392				$ 25,000