The state of Florida is passing legislation that would require about 1,600 cities, counties, and special districts in that state to report using XBRL. Florida is likely to be the first of many states that ultimately leverage the functionality of XBRL to improve their reporting systems.
In the United States there are about 90,000 state and local governmental entities.
I don't understand the process in the state of Florida; but what I can say is that the bill passed the House, it passed the Senate unanimously, and it is likely to be signed into law by the governor. I guess this will play out over the next several days or weeks.
Look at the legislation lines 319 to 350 (on the left hand side of the PDF). You can track the history of the legistlation here.
Reck and Snow paper:https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2474922