This article investigates the close partnership between linguistic typology and language documentation. It concentrates on the contributions of documentation to typology, particularly in shaping efforts to define universals and to make sense of linguistic diversity. The article then examines the importance of typology to the documentary enterprise and a typology's role in informing the representation of a language, ensuring its accessibility, and identifying ways in which it may be further refined. Linguistic typology and documentary linguistics share much of the same architecture: a common theoretical framework, an awareness of cross-linguistic similarity and variability, and a goal of forming and representing generalizations over diverse realizations. The link between linguistic typology and language documentation has developed into a rich and productive symbiosis, and its continued fruitfulness will be guaranteed by each sub-field's increasing participation in the other.