Bob Schneider is a Partner in 
Wilson So is the Director of Hitachi Consulting Corporation XBRL: Assurance Cost and Disclosure Neutrality
Written by Christian Dreyer Posted on January 16, 2008
Christian Dreyer, CFA, is a past President of the Swiss CFA Society, a 1,700-member-strong association of finance professionals in Switzerland. He is Managing Partner of Tertium datur AG, an advisor specializing in pan-European pension funds. Previously he was CFO of an IT outsourcing firm and head of investment research at a Swiss state bank. He is on the IASB’s Strategic Advisory Council for XBRL.
Skepticism about XBRL seems to abound lately, although most of it is easily soothed. One issue stands out that may raise the hackles of preparers particularly: If XBRL were to have the same costs as Sarbanes-Oxley Section 404 implementation because of independent assurance, as one Reuters story suggests, that would be a big No-No indeed.
However, looking at the Committee’s draft memo (page 75 and after), such dramatic headlines need to be taken with a ton of salt. Substantive assurance costs (if any) are likely to arise only if the production of XBRL formatted data were implemented in the least competent way imaginable, i.e., by means of what might be described as a parallel XBRL track of accounting. To assume that this is the default practice would not exactly reflect high expectations with regards to the professional competence of finance departments.
One of the basic tenets of XBRL disclosure is that it is in fact disclosure neutral, i.e., the numbers displayed in an XBRL instance document are identical to what is reported on (electronic) paper. For as long as XBRL filing is not the exclusively permitted way of filing, assurance of disclosure neutrality probably satisfies the needs of most users of financial statements. In a reasonably well structured accounting & auditing cycle, such assurance should come cheaply.