A strategy document explains the strategy. It documents the strategy and the thinking behind the strategy. A strategic plan details the plans to achieve that strategy. It documents the how plans for how the strategy will be implemented. It is a plan. it is not a strategy
These ideas and documents serve quite different purposes — they should be different types of documents.
We see a lot of plans that leave out the underlying thinking and rationale for the decisions embedded in the strategy. It makes it much harder to explain the story of the strategy, and much harder for people to interpret the actions for themselves. They just have to follow the plan.
Of course, a strategy must be implementable — it doesn’t exist without action. But it’s one thing to explain the strategies and actions that accompany it. It is something else to explain the detailed plans of the strategy.
A good strategy document has an explanation — a basis for more detailed plans, and programs of change to be derived. A document that explained the strategy and the thinking behind the strategy.