IDisposable implementation for entity framework DbContext

I have a private field that holds instance of dbContext in my class that i am initialize in the class constructor.  
I would like to implement IDisposable interface on that class so it will execute dbContext.dispose when disposing.

I am not sure if i need to do something in ~BaseDal() and in Dispose() function.

In other words, if i am using  dbContext.Dispose() in my Dispose(bool disposing) function. is means i am releasing only manage code or also unmanage code?

public class ContextHolder:IDisposable
    {
        private MyDbContext _dbContext;
        ContextHolder()
        {
            _dbContext = new JungleDbContext();
        }

        public DbRawSqlQuery<TElement> ExecuteSP<TElement>(string spName, params object[] parameters)
        {
                return _dbContext.Database.SqlQuery<TElement>(spName, parameters);
        }

        #region IDisposable Support
        private bool disposedValue = false; // To detect redundant calls

        protected virtual void Dispose(bool disposing)
        {
            if (!disposedValue)
            {
                if (disposing)
                {
                    _dbContext.Dispose();
                }

                // TODO: free unmanaged resources (unmanaged objects) and override a finalizer below.
                // TODO: set large fields to null.

                disposedValue = true;
            }
        }

        // TODO: override a finalizer only if Dispose(bool disposing) above has code to free unmanaged resources.
        // ~BaseDal() {
        //   // Do not change this code. Put cleanup code in Dispose(bool disposing) above.
        //   Dispose(false);
        // }

        // This code added to correctly implement the disposable pattern.
        public void Dispose()
        {
            // Do not change this code. Put cleanup code in Dispose(bool disposing) above.
            Dispose(true);
            // TODO: uncomment the following line if the finalizer is overridden above.
            // GC.SuppressFinalize(this);
        }
        #endregion
    }