As of the census of 2000, there were 20,411 people, 8,958 households, and 5,885 families residing in the city. The population density was 1,142.2 people per square mile (441.0/km²). There were 9,546 housing units at an average density of 534.2/sq mi (206.3/km²). The racial makeup of the city was 94.52% White, 3.86% African American, 0.11% Native American, 0.59% Asian, 0.01% Pacific Islander, 0.14% from other races, and 0.77% from two or more races. Hispanic or Latino of any race were 0.68% of the population.
There were 8,958 households out of which 23.8% had children under the age of 18 living with them, 51.4% were married couples living together, 10.6% had a female householder with no husband present, and 34.3% were non-families. 30.8% of all households were made up of individuals and 15.9% had someone living alone who was 65 years of age or older. The average household size was 2.25 and the average family size was 2.79.
The age distribution is 19.2% under the age of 18, 6.6% from 18 to 24, 26.5% from 25 to 44, 25.4% from 45 to 64, and 22.3% who were 65 years of age or older. The median age was 44 years. For every 100 females there were 88.6 males. For every 100 females age 18 and over, there were 85.6 males.
The median income for a household in the city was $35,212, and the median income for a family was $42,466. Males had a median income of $37,129 versus $19,745 for females. The per capita income for the city was $18,853. About 8.0% of families and 10.3% of the population were below the poverty line, including 14.0% of those under age 18 and 7.9% of those age 65 or over.