Detecting refactorings in commit history is essential to improve comprehension to code changes on code reviews, and to provide valuable information for empirical studies on software evolution. Techniques have been proposed to accurately detect refactorings on the granularity of a single commit. However, refactorings can be made over multiple commits because of its complexity or other real development problems, which cause detecting only on the granularity of a single commit not enough. We observe that some refactorings can only be detected in coarser granularity; i.e., changes among multiple commits. This type of refactoring is named coarse-grained refactoring in this paper. To have a better understanding of coarse-grained refactorings, we compared the detected refactorings in different granularity of commits from 19 open-source repositories. Results show that coarse-grained refactorings are common, and their appearance frequency increases with the granularity becoming coarser. In addition, we found that Move-related refactorings tended to be the most frequent coarse-grained refactoring. We also analyzed the cause of why coarse-grained refactorings happen. We suggest coarse-grained refactoring to be valued in refactoring research.