Name:	ibm_DisposalGroupNotDiscontinuedOperationEstimatedGainLossOnDisposal
Namespace Prefix:	ibm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Represents the consideration to be received, net of closing date working capital adjustments, for the sale of a business that is not a discontinued operation.

No definition available.

Name:	ibm_DisposalGroupNotDiscontinuedOperationsTransactionPrice
Namespace Prefix:	ibm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the ownership percentage to be acquired at the closing date in newly established holding company in sale of business transaction.

No definition available.

Name:	ibm_OwnershipPercentageToBeAcquiredInHoldingCompanyDuringPeriodInSaleOfBusinessTransaction
Namespace Prefix:	ibm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the period of time over which stated ownership percentage in newly established holding company is received following the closing of the transaction.

No definition available.

Name:	ibm_PeriodToReceiveOwnershipPercentageInSaleOfBusinessTransaction
Namespace Prefix:	ibm_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The cash inflow associated with the amount to be received at the closing date from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

No definition available.