“Martha,” R.J. Cutler’s film about the life and career of Martha Stewart (it drops today on Netflix), is a splendid documentary. It’s a movie that captures how Martha Stewart’s penetration into American culture seems, in hindsight, as inevitable as it was unlikely. It traces how she started off as a model, then became a New York stockbroker, then moved with her publishing-magnate husband to Westport, Conn., where they bought a fixer-upper, Turkey Hill Farm, whose fixing up, by Martha (she hand-painted the entire farmhouse while listening to the Watergate hearings), became the prototype for her brand of obsessively tasteful rustic “perfection.” It shows us how she launched a prestige catering business and then, with the 1982 book “Entertaining,” launched herself as the doyenne of a new upscale lifestyle culture that would be — in a word — vicarious.

The movie shows us that Stewart had a vision, and that her...