Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Condensed Consolidated Balance Sheets [Abstract]
Accounts receivable, reserves	$ 3,504	$ 3,239
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares issued	99,568,000	99,229,000
Deferred stock units, outstanding	122,000	119,000
Treasury stock, shares	44,507,000	44,128,000