Meloni’s move to premium cable — for which he turned down an $8 million offer to return for a thirteenth season of "SVU" — came as a bit of a shock, especially given the uncertain job security of "True Blood", a show with a tendency to off its main characters.

Some speculated that his exit was tied to the departure of "SVU’s" longtime showrunner, Neal Baer, but Meloni denies this, saying simply, “Twelve years. I never dreamed that I would stick with something for so long. I enjoyed it so much. But it was time. I had been thinking about it for a while.”

http://www.vulture.com/2012/06/chris-meloni-true-blood.html