Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Allowance for doubtful accounts	$ 7.1	$ 10.9
Stockholders’ equity (Note 14):
Common stock, par value per share (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	52,227,511	51,953,354
Common stock, shares outstanding (in shares)	46,152,958	46,116,670
Treasury stock, shares (in shares)	6,074,553	5,836,684