I need to store multiple currencies in SQL server. I understand that SQL won't support all different types of currencies (unless I store it as a string, but I don't want to do that).

My idea was to convert all the values from their currency format to a standard double and store that instead. Then just re-format based on the culture info when displaying. However, I have tried doing something like e.g.

var cultureInfo = new System.Globalization.CultureInfo("en-US");
double plain = return Double.Parse("$20,000.00", cultureInfo);

This doesn't ever seem to work it always throws a FormatException. Even removing the currency symbol and just trying to do this based on the number alone does the same thing. This is just an example I want to support pretty much any type of currency.

Is there a standard way of stripping out currency and getting the value as a double?