As of the 2000 census, there were 18,307 people, 7,510 households and 4,889 families residing in the city. The population density was 2,497.9 people per square mile (964.3/km²). There were 8,030 housing units, at an average density of 1,095.6/sq mi (423.0/km²). The racial makeup of the city was 95.26% White, 1.37% African American, 0.15% Native American, 0.83% Asian, 0.06% Pacific Islander, 0.93% from other races and 1.39% from two or more races. Hispanic or Latino of any race were 5.21% of the population.
There were 7,510 households out of which 31.1% had children under the age of 18 living with them, 49.4% were married couples living together, 11.7% had a female householder with no husband present and 34.9% were non-families. 30.8% of all households were made up of individuals and 14.2% had someone living alone, who was 65 years of age or older. The average household size was 2.38 and the average family size was 2.98.
In the city, the population was spread out with 24.9% under the age of 18, 8.1% from 18 to 24, 28.2% from 25 to 44, 20.8% from 45 to 64 and 17.9% who were 65 years of age or older. The median age was 38 years. For every 100 females, there were 91.3 males. For every 100 females age 18 and over, there were 87.3 males.
The median income for a household in the city was $36,513 and the median income for a family was $44,435. Males had a median income of $41,943 versus $22,041 for females. The per capita income for the city was $19,426. About 9.8% of families and 11.3% of the population were below the poverty line, including 16.8% of those under age 18 and 7.0% of those age 65 or over.