Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Allowance for doubtful accounts	$ 1.7	$ 1.8
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	18,563,056	18,479,684
Common stock, shares outstanding (in shares)	18,563,056	18,479,684