A detailed investigation into the complexities and limitations of XBRL Calculations
by: Shawn Rush,
CompSci Resources, LLC
The first thing to notice is that "NetCashProvidedByUsedInOperatingActivities" lacks a balance type, which may seem odd at first. Given that this is a component of "Cash and Cash Equivalents," one might expect this concept to be a debit. Additionally, both "NetCashProvidedByUsedInFinancingActivities" and "NetCashProvidedByUsedInInvestingActivities" are debits.
If, however, "NetCashProvidedByUsedInOperatingActivities" were a debit, we would not be able to create the following calculation:
ProfitLoss + DepreciationDepletionAndAmortization = NetCashProvidedByUsedInOperatingActivities
If "NetCashProvidedByUsedInOperatingActivities" were a debit, then we would be forced to subtract "ProfitLoss" which does not make sense here. Fortunately, "NetCashProvidedByUsedInOperatingActivities" does not have a balance type so we are free to create the above calculation. Additionally, a portion of the definition for this concept appears to support this reason for no balance type:
While for technical reasons this element has no balance attribute, the default assumption is a debit balance
consistent with its label.
Another issue that causes confusion with the cash flows statement is a calculation that exists in the income statement but in reverse fashion. Consider the following example from the income statement:
Sometimes you could see the exact same items in the cash flows statement but in reverse order such as the following:
Creating a calculation for the income statement is not a problem, but we cannot create the calculation in the exact form that is presented in the cash flows statement. From the income statement, we have the following equation:
IncomeLossFromContinuingOperations + IncomeLossFromDiscontinuedOperationsNetOfTax + DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax = NetIncomeLossAvailableToCommonStockholdersBasic
Algebra tells us that we can rewrite this equation as follows:
IncomeLossFromContinuingOperations = NetIncomeLossAvailableToCommonStockholdersBasic - DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax - IncomeLossFromDiscontinuedOperationsNetOfTax