The Redskins lose $36M off their cap, the Cowboys $10M. Half must be taken this year, half next year. The other teams split the money, $1.6M per team added to their cap and can use it however they want over two years.
Basically during the uncapped year teams were given a "estimated" cap number they would have if their was a cap and told that it was possible they might he held to it retroactively in future deals, so be responsible (it's not official but this is what people are reporting). The Skins, Cowboys, Raiders and Saints (the latter two in a small way) tried to circumvent things by frontloading contracts into that open year.
Stupid stupid stupid.
So my Giants gets $1.6M more to spend, the Skins and Cowboys get less. If the Eagles were only punished too my life would be perfect.