In the field of software engineering component-based development and appropriate documentation are established methods to support reuse. While modular development is tackled in various work regarding ontology engineering, it is an open problem how documentation of ontologies should be created. After analyzing existing ontology documentations we identified grouping concepts as a very helpful technique to simplify the understandability and thus improve the reusability of ontologies. In this paper, we present a technique to group concepts for ontology documentation by applying community detection algorithms on the graph structure of ontologies. Using the manually created concept groups from existing documentations as reference we demonstrate that this technique is able to create appropriate concept groups automatically.