Friday 9 December 2011

XBRL Tags into Excel using Arelle

I've finally found a piece of free software that will put the data with the tags into Excel. Using Arelle is not the most elegant of solutions but it will do it.

Arelle is essentially an open source project that has created a XBRL parser and related tools. It's functionality is exposed via a Python API but crucially they have also created a windows (and OS X) app that can be accessed from a GUI or the command line.

The GUI lets you get a number of views on the XBRL that you can't get anywhere else for the price. Of most interest, for an analyst trying to harness the power of XBRL in Excel, is the "Fact Table" tab.

Load up an instance document, which you can do by selecting a file from your hard drive (Arelle will even open up a zipped archive) or the web by supplying a URL such as the path to the document in Edgar*, or you can choose to download the SEC RSS feed which will list the latest filings in a tab marked "RSS". You can then right click on a filing to open the instance document, which is kinda neat. Once it's loaded (this may take some time whilst it downloads the countless schemas or forever if the site is down!), a series of tabs will appear on the top right hand side of the app. You can load more than one instance document at a time in which case the tabs will be replicated, with unfortunately no indication as to which tabs belong to which.

In the "Fact Table" tab you will see a list of statements which can be expanded to reveal the presented items with YES! the XBRL tags next to the data values. You may see an awful lot of unnecessary periods (or dimensions as those XBRL types like to call them) running across the top. Some of these may disappear if you right click anywhere in the table and choose the "ignore dimensions" option. No idea what it's supposed to do but I have seen useless columns vanish.

Now you can right click again to "expand all" rows, select the rows you want in the usual manner and right click again to "copy to clipboard". If you're feeling lazy and enjoy swimming in data, don't bother expanding and selecting rows, just (you've guessed it) right click and "copy to clipboard" the whole table - and it means the whole of it, not just a statement table.

Now for the magic bit - when you get to Excel, the XBRL tags HAVEN'T mysteriously disappeared! Who-hay! Now at last we can seriously consider some comparative analysis! which needless to say I'll be doing in a couple of posts time. Next up I feel I should finish off talking about Arelle and in particular whether the command line creates any useful options.

*You can quickly find the path using XBRL XL. Search for your chosen document and click on the document type (e.g. 10K) which will take you to the Edgar filing page. Right click on the instance document (invariably the first "data file") and copy the address.

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