Ideas are generally something you can put into practice, thoughts are the minds wandering, like that flower is pretty, or, its a warm day.

Idea: 1. a suggestion or plan for doing something - "She's full of bright (= good) ideas." 2. a belief or opinion - "We have very different ideas about disciplining children." 3. a purpose or reason for doing something - "The whole idea (= only purpose) of advertising is to make people buy things." thought: 1. the product of mental activity; that which one thinks: a body of thought. 2. a single act or product of thinking; to collect one's thoughts. 3. the act or process of thinking; mental activity: Thought as well as action wearies us. 4. the capacity or faculty of thinking, reasoning, imagining, etc.: All her thought went into her work. 5. a consideration or reflection: Thought of death terrified her. 6. meditation, contemplation, or recollection: deep in thought. 7. intention, design, or purpose, esp. a half-formed or imperfect intention: We had some thought of going. 8. anticipation or expectation: I had no thought of seeing you here. 9. consideration, attention, care, or regard: She took no thought of her appearance. 10. a judgment, opinion, or belief: According to his thought, all violence is evil. 11. the intellectual activity or the opinions; characteristic of a particular place, class, or time: Greek thought. 12. a very small amount; a touch; bit; trifle: The steak is a thought underdone. Idea is a simpler form of thought - the former can never replace the later. The word thought has many in-depth meanings. We never use the word idea in expressions like "philosophical thought". What children get are called ideas and never called thoughts.

I would say an idea is a specific kind of thought. For example, you can have thoughts about being cold, and wondering about the weather, and then get an idea to put on a sweater.

my ideas actually turn out to be something... my thoughts are totally random :)