Split Hairs Meaning

(idiomatic) Tedious details; minutiae.

Example: 1999, Lev Grossman, "Microsoft Tangled Up in Videotape Evidence," Time, 4 Feb.,
  The Microsoft trial had been in danger of slipping out of the public eye. Its endless procession of less-than-riveting economics professors and forgetful executives, mixed with scads of legal and technical split hairs, just hasn't made for gripping headlines.