Housebreaking a new puppy?

So I just got a puppy a few weeks ago. And when we first got him, he did great with the whole going outside for the bathroom thing, with a few accidents at night. So we put down good old fashioned newspaper for when he went at night. Well now he thinks that that is his potty place, and that outside time is play time. So I take him outside and he runs around for like, 20 minutes, comes inside, and pees on the floor. And now he tears up the newspapers and most of whatever room he is in whenever I am not home. What should I do?