Lipitor wasn't an idea, it was the result of research followed by intensive development. Synthesis of an organic salt tends to be non-trivial. FDA approval is left as an exercise for the reader.
Atorvastatin was first synthesized in 1985 by Bruce Roth of Parke-Davis Warner-Lambert Company (now Pfizer). The best selling drug in pharmaceutical history, sales of Lipitor since it was approved in 1996
Even after you've developed the method of synthesis, you still have to actually do it at scale, market it, and as you mentioned, get FDA approval. That all counts as execution.
Atorvastatin was first synthesized in 1985 by Bruce Roth of Parke-Davis Warner-Lambert Company (now Pfizer). The best selling drug in pharmaceutical history, sales of Lipitor since it was approved in 1996
http://en.wikipedia.org/wiki/Lipitor