AngularJS - Calculating length of JSON array

I have a set of JSON data and within it, i am trying to calculate the length of an array (Infos):

My JSON:

    "Association": {
    "Items": [
         {
            "AssocName": {
                "SurName": "BLOGGS",
                "Title": "MR",
                "ForeName": "HAPPY"
            },
            "Details": [
                {
                  "Name": {
                        "SurName": "BLOGGS",
                        "Title": "MR",
                        "ForeName": "HAPPY"
                    },
                   "Infos": [
                      {
                         //Some Data
                         //Some Data
                         //Some Data
                      },
                      {
                         //Some Data
                         //Some Data
                         //Some Data
                      },
                      {
                         //Some Data
                         //Some Data
                         //Some Data
                      },
                      {
                         //Some Data
                         //Some Data
                         //Some Data
                      }
                    ]
                 }
             ]
        },
        {
            "AssocName": {
                "SurName": "BLOGGS",
                "Title": "MRS",
                "ForeName": "BLUE"
            },
            "Details": [
                {
                  "Name": {
                        "SurName": "BLOGGS",
                        "Title": "MRS",
                        "ForeName": "BLUE"
                    },
                   "Infos": [
                      {
                         //Some Data
                         //Some Data
                         //Some Data
                      },
                      {
                         //Some Data
                         //Some Data
                         //Some Data
                      }                     
                   ]
               }
            ]
        }
    ]
}

My HTML:

<tr ng-repeat-start="associations in Association.Items track by $index">
    <td>
        {[{associations.AssocName.Title}]}
        {[{associations.AssocName.ForeName}]}
        {[{associations.AssocName.SurName}]}
    </td>
    <td>
        {[{ associations[$index].Details.Infos.length }]} of Details
    </td>
</tr>

But no valus seems to be displayed... The Title, Forename and Surname are displaying as expected.