Whether old money, New Money, royalty, or nobility, these people just spend their time living off their vast sums of money they earned, or their family's sums of money. Not to say they just sit around doing nothing (usually). They have too much of their free time taken up by travelling, going to parties and galas, attending horse races and polo matches, keeping up with the latest Society gossip, choosing which clothes to wear, spoiling Mister Muffykins rotten, and occasionally doing at least some token work in their family business. So they can't really be idle. They're too rich to be.