regex detect segments in structured textfile

Question

I'm looking for a RegEx pattern which detects sections in the structured textfile below:

RecordHeader of Isotemplate   1
   <Data>
 FingerViewHeader IndexNr   0
   <Data>
 MinutiaIndex:   0
   <Data>
 MinutiaIndex:   1
   <Data>
RecordHeader of Isotemplate   2
   <Data>
 FingerViewHeader IndexNr   0
   <Data>
 MinutiaIndex:       0
   <Data>
 MinutiaIndex:       1
   <Data>

I need the whole multiline text from one RecordHeader to the next. There can be any number of FingerViews and Minutiae in between.

I tried (and of course many others..)

(RecordHeader)(.+\n)+(?=RecordHeader)

but this matches the whole file without stopping at the next RecordHeader (At least http://regexhero.net/tester/ did so).

Is this a good approach? It doesn't even need to be fast.