CONSOLIDATED CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Accounts receivable, allowance for doubtful accounts (in dollars)	$ 4.0	$ 4.2
Preferred Stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred Stock, shares authorized	100,000	100,000
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common Stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common Stock, shares authorized	240,000,000	240,000,000
Common Stock, shares issued	85,314,863	89,524,724
Common Stock, shares outstanding	85,314,863	89,524,724
Non-voting Common Stock
Common Stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common Stock, shares authorized	7,125,000	7,125,000
Common Stock, shares issued	0	0
Common Stock, shares outstanding	0	0
Class C Common Stock
Common Stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common Stock, shares authorized	20,000,000	20,000,000
Common Stock, shares issued	0	0
Common Stock, shares outstanding	0	0