Boeing Defense doesn't make a whole lot of surplus cash either.[1] They've eaten some large expenses in the last 2 years (KC-46 tanker cost overrun, Advanced Super Hornet development program) and probably others. I don't believe there is significant cash flow over to Boeing Commercial Aircraft. There is exceptions like the KC-46 and P-8, but most programs are Boeing Defense only with almost no crossover.
The Boeing 737NG line is probably their most profitable product overall. That is from Boeing Commercial Aircraft.
"Boeing Defense doesn't make a whole lot of surplus cash either"
It does give you economies of scale in the sense that any larger company gains purchasing power and for that matter visibility (and political power) by employing more people.
The Boeing 737NG line is probably their most profitable product overall. That is from Boeing Commercial Aircraft.
Some financials for your reference [1] http://boeing.mediaroom.com/index.php?s=20295&item=128736