Fast National ratings for Tuesday Dec. 16, 2008.

The finale of NBC's "Biggest Loser: Families" helped give the network a demo split on Tuesday night, but CBS' procedurals swept the evening in total viewers.

CBS and NBC posted matching 3.8 ratings in the key 18-49 demographic, easily beating FOX's 2.2 rating and the 2.0 rating for ABC. The CW limped along with a 0.4 rating.

Overall, though, CBS averaged nearly 17.9 million viewers for the night, plus a 10.9 rating/17 share. NBC was a distant second with a 6.1/10. ABC's 3.7/6 and the 3.6/6 for FOX followed. The CW's 0.8 rating wasn't in the mix.

CBS kicked the night off with a 12.0/19 for "NCIS," trumping the 6.5/20 for the first hour of "Biggest Loser: Families." ABC was third with the ever-popular "Charlie Brown Christmas." FOX's "House" was fourth with a 4.2/6 and The CW trailed with "90210."

"The Mentalist" gave CBS the 9 p.m. hour with an 11.6/18. NBC's "Biggest Loser: Families" improved to a 7.8/12 in its second hour. Note: "Biggest Loser: Families" beat the CBS procedurals in the 18-49 demo for both of its hours. Also at 9 p.m., ABC's "According to Jim" and "Fringe" tied for third. The CW's "Privileged" was fifth with a 0.7/1.

"CSI: NY" closed out the CBS sweep with a 9.2/16 at 10 p.m. Described by NBC's promo department as "the year's most anticipated show," "Momma's Boys" had a 4.1/7. ABC's "Eli Stone" trailed.

All ratings information comes from preliminary Fast National data, which includes live and same-day DVR viewing. All numbers are subject to change.