BUG: idxmin and idxmax raising ValueError with all nan row
- [x] closes #48123 (Replace xxxx with the Github issue number)
- [x] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [x] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [x] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

The Int64 case was working before too. Just added this for consistency
Probably worth noting the [documentation ](https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.idxmax.html) should be modified as it says an exception is raised if there is a row / column that only contains NaN / NaT / .... I don't know if this is usually done within PRs? Not sure what this is referencing exactly, this could also mean an empty object, e.g. no values at all Was running the wrong tests obviously. The ValueError seems to be the expected behaviour So is it fixed? Sorry not sure I get what you meant Raising would be expected here Yes but a fix is still needed since integers and timedelta datatypes don't behave the same way right?