Adding total row to pandas DataFrame groupby

Categories
Level      Company         Item
    1            X            a                             100
                              b                             200
                 Y            a                              35
                              b                             150
                              c                              35
    2            X            a                              48
                              b                             100
                              c                              50
                 Y            a                              80
m = df.groupby(['Level','Company','Item'])['Value'].sum().unstack(level=['Company','Item'])
m = m.assign(total=m.sum(1))
m = m.stack(level='Company')
m = m.assign(total=m.sum(1))
m = m.stack(level='Item')
Level  Company  Item 
1      X        a        100.0
                b        200.0
                total    300.0
       Y        a         35.0
                b        150.0
                c         35.0
                total    220.0
       total             520.0
                total    520.0
2      X        a         48.0
                b        100.0
                c         50.0
                total    198.0
       Y        a         80.0
                total     80.0
       total             278.0
                total    278.0
dtype: float64