Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2012	Dec. 31, 2011
Allowance for doubtful accounts	$ 3,939,000	$ 4,506,000
Accumulated amortization of other intangible assets	$ 9,535,000	$ 7,909,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	69,911,000	69,473,000
Common stock in treasury, shares	2,210,000	2,684,000