But I thought Fox was a cable channel

From www.cynopsis.com

Fox 11.1/17 American Idol Day 16.2/24, State of the Union Address 6.1/9
CBS 5.6/9 NCIS [r], 7.6/11 State of the Union Address 4.7/7
ABC 4.1/6 According to Jim [r] 4.2/6, Rodney [r] 3.8/6, State of the Union Address 4.2/7
NBC 3.8/6 Fear Factor 3.2/5, State of the Union Address 4.1/6

A18-49: Fox 8.0/20, WB 2.4/6, ABC 2.1/5, CBS and NBC 2.0/5, Univision 1.9/5, UPN 0.8/2, Telemundo 0.6/1 Source: Nielsen Media Research.