The second year of the SEC's XBRL mandate provides compliance challenges that impact nearly 2,000 of the world’s largest public companies. In addition, many public companies are entering into their initial year of the mandate and can benefit from lessons learned by the first wave of companies. The SEC staff held a public seminar on March 23, 2010 and continues to update their compliance and disclosure interpretations and frequently asked questions to provide additional guidance about compliance with the final rules. Preparers will want to take advantage of the lessons learned to date as they plan to meet the upcoming requirements. This PwC Dataline describes recent guidance provided by the SEC staff and offers other helpful information and reminders for preparers.