Decrease detail density with distance?

I need to lower my detail density or viewing distance or else I go over the 65k verts limit. Decreasing the viewing distance of details really breaks immersion when the grass just abruptly stops. Changing the detail density depending on distance would be a nice way to fade-away the grass. Is it possible to decrease the detail density depending on distance from the player? Shaders? Would this require to split up the terrain in many small pieces and dynamically set the detail density or is there an easier way?