Insert complex XML into SQL Server table

Given this XML:

<Documents>
  <Batch BatchID="1" BatchName="Fred Flintstone">
    <DocCollection>
      <Document DocumentID="269" FileName="CoverPageInstructions.xsl">
        <MergeFields>
          <MergeField FieldName="A" Value="" />
          <MergeField FieldName="B" Value="" />
          <MergeField FieldName="C" Value="" />
          <MergeField FieldName="D" Value="" />
        </MergeFields>
      </Document>
      <Document DocumentID="6" FileName="USform8802.pdf">
        <MergeFields>
          <MergeField FieldName="E" Value="" />
          <MergeField FieldName="F" Value="" />
          <MergeField FieldName="G" Value="" />
          <MergeField FieldName="H" Value="" />
          <MergeField FieldName="I" Value="" />
        </MergeFields>
      </Document>
      <Document DocumentID="299" FileName="POASIDE.TIF">
        <MergeFields />
      </Document>
    </DocCollection>
  </Batch>
  <Batch BatchID="2" BatchName="Barney Rubble">
    <DocCollection>
      <Document DocumentID="269" FileName="CoverPageInstructions.xsl">
        <MergeFields>
          <MergeField FieldName="A" Value="" />
          <MergeField FieldName="B" Value="" />
          <MergeField FieldName="C" Value="" />
          <MergeField FieldName="D" Value="" />
        </MergeFields>
      </Document>
      <Document DocumentID="6" FileName="USform8802.pdf">
        <MergeFields>
          <MergeField FieldName="E" Value="" />
          <MergeField FieldName="F" Value="" />
          <MergeField FieldName="G" Value="" />
          <MergeField FieldName="H" Value="" />
          <MergeField FieldName="I" Value="" />
        </MergeFields>
      </Document>
    </DocCollection>
  </Batch>
</Documents>

I'm trying to achieve this result:

BatchID BatchName DocumentID FieldName
1   Fred Flintstone 269 A
1   Fred Flintstone 269 B
1   Fred Flintstone 269 C
1   Fred Flintstone 269 D
1   Fred Flintstone 6   E
1   Fred Flintstone 6   F
1   Fred Flintstone 6   G
1   Fred Flintstone 6   H
1   Fred Flintstone 6   I
1   Fred Flintstone 299 Null
2   Barney Rubble   269 A
2   Barney Rubble   269 B
2   Barney Rubble   269 C
2   Barney Rubble   269 D
2   Barney Rubble   6   E
2   Barney Rubble   6   F
2   Barney Rubble   6   G
2   Barney Rubble   6   H
2   Barney Rubble   6   I

I seems to be getting a Cartesian JOIN with this (each document has the full list of MergeField across all documents:

SELECT lvl1.n.value('@BatchID','int'), 
       lvl1.n.value('@BatchName','varchar(50)'), 
       lvl2.n.value('@DocumentID','int'), 
       lvl3.n.value('@FieldName','varchar(50)') 
FROM  @Data.nodes('Documents/*') lvl1(n)
CROSS APPLY lvl1.n.nodes('DocCollection/Document') lvl2(n)
CROSS APPLY lvl1.n.nodes('DocCollection/Document/MergeFields/MergeField') lvl3(n)   

And am wondering how to get the result I need, with a Null value for the 299 DocumentID in Batch 1 that has no MergeField elements.

Any help is appreciated.

Thanks

Carl

UPDATE: Here's how to do the same using OpenXML:

 SELECT   
   BatchID,   
   BatchName,   
   DocumentID,   
   FileName,   
   KeyData,   
   FieldName  
   FROM OPENXML(@hdoc, '/Documents/Batch/DocCollection/Document/MergeFields/MergeField', 11)  
      WITH (BatchID varchar(100) '../../../../@BatchID',  
            BatchName varchar(100) '../../../../@BatchName',   
            DocumentID varchar(100) '../../@DocumentID',  
            FileName varchar(100) '../../@FileName',   
            KeyData varchar(100) '../../@KeyData',   
            FieldName varchar(100) '@FieldName');