Condensed Consolidated Balance Sheets Parentheticals (USD $) In Millions, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Allowance for doubtful accounts	$ 10.1	$ 10.9
Stockholders' equity:
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	12,705,542	12,602,806
Common stock, shares outstanding	11,476,858	11,446,229
Treasury stock, shares	1,228,684	1,156,577