The present invention provides for novel compounds of Formula (I) and pharmaceutically acceptable salts and co-crystals thereof which have glucagon receptor antagonist or inverse agonist activity. The present invention further provides for pharmaceutical compositions comprising the same as well as methods of treating, preventing, delaying the time to onset or reducing the risk for the development or progression of a disease or condition for which one or more glucagon receptor antagonist is indicated, including Type I and II diabetes, insulin resistance and hyperglycemia. The present invention also provides for processes of making the compounds of Formula I, including salts and co-crystals thereof, and pharmaceutical compositions comprising the same.