CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Allowance for doubtful accounts	$ 11.0	$ 7.7
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	139,602,483	118,125,652
Common stock, shares outstanding (in shares)	137,435,090	115,958,259
Treasury stock (in shares)	2,167,393	2,167,393
Series B Preferred stock ($0.01 par value, 1,000,000 shares authorized, no shares issued and outstanding)
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Series C Preferred stock ($0.01 par value, 18,500 shares authorized, no shares issued and outstanding)
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	18,500	18,500
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Series D Preferred stock ($0.01 par value, 5,000 shares authorized, 883 shares issued and outstanding)
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000	5,000
Preferred stock, shares issued (in shares)	883	883
Preferred stock, shares outstanding (in shares)	883	883