broad strokes

The President made his proposals in broad strokes, and the details remain to be worked out.

Maurice hastily climbed the fence, and while he was thus occupied Mr. Samuel Williams received a great enlightenment. With startling rapidity Penrod, standing just outside the storeroom door, extended his arm within the room, deposited the licorice water upon the counter of the drug store, seized in its stead the bottle of smallpox medicine, and extended it cordially toward the advancing Maurice.

Genius is like that—great, simple, broad strokes!