'Dexter' finale a boost for Showtime

Network's most-watched telecast since 2004

"Dexter" killed for Showtime in its third-season finale Sunday night.

The drama drew 1.5 million total viewers at 9 p.m., making it the premium network's most-watched telecast since 2004, when Nielsen began reporting Showtime ratings separate from Showtime Plex. That's up 7% compared with the Season 2 finale (1.4 million) and a 25% improvement over the first-season closer (1.2 million). An 11 p.m. repeat drew 491,000 viewers.

Meanwhile, the Season 2 finale of "Californication" at 10 p.m. averaged 615,000 viewers, a season high. A 10:30 p.m. repeat of the comedy pulled in 322,000 viewers.

"Dexter" already has been renewed for two more seasons, while "Californication" recently got the green light for its third season.

In other cable ratings news, the sixth-season premiere of A&E's "Intervention" averaged 2.2 million total viewers -- including 1.6 million adults 25-54 and 1.7 million adults 18-49 -- at 9 p.m. Monday. That marks the series' best bow in all key demos.