Condensed Consolidated Balance Sheets Parentheticals (USD $) In Millions, except Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Allowance for doubtful accounts	$ 9.8	$ 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	12,758,985	12,602,806
Common stock, shares outstanding	11,524,799	11,446,229
Treasury stock, shares	1,234,186	1,156,577