WPF Treeview: Styling and Template Binding using MVVM

<UserControl x:Class="TreeViewStyleTemplate.View.CompanyDetailView"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             mc:Ignorable="d"
             d:DesignHeight="300"
             d:DesignWidth="300">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="40" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <Grid Grid.Row="0">
            <TextBlock Text="XYZ Company"
                       Style="{DynamicResource TextBlockStyle}" />
        </Grid>
        <Grid Grid.Row="1">
            <Grid.RowDefinitions>
                <RowDefinition Height="40" />
                <RowDefinition Height="*" />
            </Grid.RowDefinitions>
            <Grid Grid.Row="0">
                <TextBlock Text="Department List"
                           Style="{DynamicResource TextBlockStyle}"
                           FontSize="12" />
            </Grid>
            <Grid Grid.Row="1"
                  MaxHeight="250">
                <TreeView ScrollViewer.VerticalScrollBarVisibility="Auto"
                          BorderThickness="0"
                          Background="#FFF"
                          ItemContainerStyle="{DynamicResource TreeViewItemStyle}"
                          ItemsSource="{Binding DepartmentCollection}"
                          ItemTemplate="{DynamicResource DepartmentTemplate}" />
            </Grid>
        </Grid>
    </Grid>
</UserControl>