How can I add items in a query to the List<StudentDetails> ?

using JSON:

 [WebMethod]
        public StudentDetails[] GetTodayReport(int StudentID, DateTime startdate)
        {
            try
            {
                context = new TMSEntities();
                List<studentdetails> details = new List<studentdetails>();
                List<string> sdetails = new List<string>();
                DataTable NewTable = new DataTable();
                NewTable.Columns.AddRange(new DataColumn[6] { new DataColumn("Type", typeof(string)), new DataColumn("StartDate", typeof(string)), new DataColumn("Name", typeof(string)), new DataColumn("Status", typeof(string)), new DataColumn("EndDate", typeof(string)), new DataColumn("Course", typeof(string)) });
                var query = (from E in context.tbl_ExamCreation
                             join EA in context.tbl_ExamAttendence on E.Exam_ID equals EA.Exam_ID
                             join C in context.tbl_Course on E.Course_ID equals C.CourseID
                             where EA.StudentID == StudentID && SqlFunctions.DateDiff("DAY", E.DateOfExam, startdate) == 0 && E.Status == "A"
                             select new { Type = "Exam", StartDate = E.DateOfExam, Name = E.ExamName, Status = EA.status, EndDate = E.ExamEndDatetime, Course = C.Name })
                           .Union
                           (from LS in context.tbl_LectureScheduling
                            join LA in context.tbl_LectureAttendence on LS.LectureScheduleID equals LA.LectureScheduleID
                            join L in context.tbl_Lectures on LS.LectureID equals L.LectureID
                            join CR in context.tbl_Course on L.CourseID equals CR.CourseID
                            where LA.StudentID == StudentID && SqlFunctions.DateDiff("DAY", LS.StartDateTime, startdate) == 0 && LS.Status == "A"
                            select new { Type = "Lecture", StartDate = LS.StartDateTime, Name = L.LectureName, Status = LA.status, EndDate = LS.EndDateTime, Course = CR.Name }
                            );
                foreach(var item in query)
                {
                   // Here I want to add above query result into "details" list which is of type   List<studentdetails> 
                }
              
            }
            catch (Exception ex)
            {
                return null;
            }
        }
    }
    public class StudentDetails
    {
        public string Type{get; set;}
        public string StartDate { get; set; }
        public string Name { get; set; }
        public string Status { get; set; }
        public string EndDate { get; set; }
        public string Course { get; set; }
    }

}