As of the census of 2000, there were 195,277 people, 70,060 households, and 51,914 families residing in the county. The population density was 295 people per square mile (114/km²). There were 73,017 housing units at an average density of 110/square mile (43/km²). The racial makeup of the county was 89.33% White, 6.36% Black or African American, 0.21% Native American, 1.67% Asian, 0.03% Pacific Islander, 0.92% from other races, and 1.47% from two or more races. 2.39% of the population were Hispanic or Latino of any race. 24.7% were of German, 12.9% American, 12.3% Irish and 10.1% English ancestry according to Census 2000.
There were 70,060 households out of which 38.60% had children under the age of 18 living with them, 61.10% were married couples living together, 9.40% had a female householder with no husband present, and 25.90% were non-families. 20.10% of all households were made up of individuals and 6.70% had someone living alone who was 65 years of age or older. The average household size was 2.72 and the average family size was 3.16.
In the county the population was spread out with 27.60% under the age of 18, 7.40% from 18 to 24, 32.70% from 25 to 44, 22.60% from 45 to 64, and 9.60% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 96.90 males. For every 100 females age 18 and over, there were 93.90 males.