A Detail Member is at the lowest level of Members and has no Child Members in a Dimension; it often is indicated by a pound/number sign (#).
Detail Members store values at Memeber intersections which in turn are stored as Fact Data within a Cube. These are indexes of axis points, for both numeric and string values: numeric values can be integers, decimal fractions or a number in scientific notation, while string values may be a combination of letters and numbers not used in a mathematical function. They are otherwise termed as the ‘Leaf Members’.