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

Amount of noncurrent assets classified as other.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(17))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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

- References

No definition available.

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

Amount of asset related to consideration paid in advance in an asset acquisition, classified as non-current.

No definition available.

Name:	yb_AssetAcquisitionPrepaidConsiderationNoncurrent
Namespace Prefix:	yb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of interest-free loans to staff after allowance for credit loss, classified as noncurrent.

No definition available.

Name:	yb_InterestFreeLoansToStaffAfterAllowanceForCreditLossNoncurrent
Namespace Prefix:	yb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of allowance for credit loss on interest-free loans to staff, classified as noncurrent.

No definition available.

Name:	yb_InterestFreeLoansToStaffAllowanceForCreditLossNoncurrent
Namespace Prefix:	yb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of interest-free loans to staff before allowance for credit loss, classified as noncurrent.

No definition available.

Name:	yb_InterestFreeLoansToStaffBeforeAllowanceForCreditLossNoncurrent
Namespace Prefix:	yb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Period between the issuance and maturity of interest-free loans.

No definition available.

Name:	yb_InterestFreeLoansToStaffMaturityTerm
Namespace Prefix:	yb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Principal amount of interest-free loans to staff.

No definition available.

Name:	yb_InterestFreeLoansToStaffPrincipalAmount
Namespace Prefix:	yb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Carrying amount as of the balance sheet date of amounts prepaid for staff compensation, classified as noncurrent.

No definition available.