The proposed 2014 U.S. GAAP Taxonomy is available for inspection, and preparers might be happy to note it contains far fewer changes compared with earlier proposals.

The Taxonomy, which companies use to complete their XBRL filings, is updated annually for changes in accounting standards, but it's also modified to make improvements as preparers and other users get more familiar with it over time. In its earliest years, the Taxonomy went through considerable changes in elements and definitions to make them clearer and assure they reflected how users were actually using the taxonomy.

“The first three releases were focused on a fair amount of cleanup that needed to be done to address common reporting practices,” says Louis Matherne, chief of Taxonomy development for FASB. The learning curve of those early years now appears to be history. “At the beginning of the year, we committed to a stable Taxonomy in 2014,” he says.

For example, the 2014 proposed Taxonomy contains 301 new elements, whereas the 2013 edition contained more than 1,000. Only 98 elements were removed from the Taxonomy for 2014; last year, they numbered nearly 1,000. Likewise, the latest edition contains only 66 changes in definitions. “Last year there were more than 1,200,” says Matherne. “That's clearly a dramatic drop-off.”

Changes to the 2014 Taxonomy do not reflect, however, many of the persistent concerns that have developed over companies' misreporting of negative values. "That is largely a best practices issues," says Matherne. "We're limited in what we can do in the Taxonomy to address that." He says the staff has made a considerable effort to modify definitions to make it clear where they contain negative values.

As the Taxonomy matures, now the staff at FASB is looking for other ways to facilitate and improve XBRL reporting, such as producing Implementation Guides and developing elements and definitions related to new accounting standards earlier in the pipeline. The staff is working, for example, on Taxonomy development for some major accounting standards that FASB is developing around revenue recognition, leasing, and financial instruments. The goal is to propose the Taxonomy amendments with the accountings changes in a single package. That's the approach taken recently when FASB issued a proposed accounting standards update on discontinued operations, says Matherne.

FASB is accepting comments on the proposed 2014 Taxonomy through Oct. 31, with the final Taxonomy expected to be published in early 2014. FASB has scheduled a webcast for Sept. 10 to explain the changes to the 2014 proposed Taxonomy, with staff of the Securities and Exchange Commission also scheduled to discuss XBRL reporting issues.