If you are using lightroom, you would have faced the same problem as me, if you are using lightroom on a narrow monitor. When you expand Detail tool, you will not be able to see all of the controls below the Detail preview.
From the above screen you can see that you cannot access the Noise Reduction without losing the sight of the detail preview screen. I find it difficult to work on noise reduction without the preview where I can see how it affects the image. Here is what I do. Instead of collapsing the detail module preview, I collapse the Histogram as Histogram does not go through any major changes for noise reduction. Here is what I get after collapsing the Histogram.
Yaay, now I can work on the detail without loosing sight of the details ;)