Most companies, whether large or small, currently outsource the tagging of their financial filings into the interactive XBRL format. But in-house solutions are becoming more attractive, in part because the two-year liability grace period is winding down. During the limited liability period that covers the first two years in which companies tag their financial filings, the Securities and Exchange Commission alerts companies to errors that need fixing. Once that period ends, errors will mean restating the company's financials.

"That's big, because restatements can end up on the front page of the Wall Street Journal," says William Sinnett, research director at Financial Executives International (FEI).

A recent FEI survey found companies are increasingly bringing the XBRL effort in-house, with nearly 100% of those that plan to change their XBRL process saying they intend to bring it in-house. Ernst & Young's research shows that over the last year, the portion of companies using an outsourcer dropped to 85% from 90%, and Paul Penler, an executive director at Ernst & Young, says he expects that to fall to 75% in 2012.