- There is absolutely *not* a requirement from to report a zero value for “all possible facts”.
- There is indeed a positive requirement *not* to report *any* value (including zero) for “facts on tables that are indicated as not reported by the filing indicator (i.e. where there is not a filing indicator for the template, or the indicator shows the template as not reported). *
- Even in the case of tables that are indicated as reported, it is not *necessary* to report zeroes.
- We would advise that “non-significant” zeroes as you have described them should generally not be reported (particularly in cases such as entire sheets of zeroes, e.g. in currency breakdowns, where doing so would clearly be horribly inefficient).
- We would advise however that “significant” zeroes (i.e. values that are known to just “happen to be” zero in this report for this period, but would not always/generally be expected to be for that institution) *should* be reported, for clarity. In other words, don’t feel the need to aggressively remove all zeroes unnecessarily.
In other words, in general use common sense – if in filling in a paper form by hand you would consider writing in zero, it is likely appropriate to include zero in the file. If on the other hand you would leave the cell blank, do not transmit the zero.
Note particularly that (in the case where reported figures are rounded or truncated) where figures only “round to zero” they *should* be reported so as to enable the indication of the rounding (using the XBRL decimal attribute on the fact), this may be necessary in order that validation test take into account the possible rounding of this value when checking numeric relations (such as comparing totals to breakdowns).