Earnings/Loss per Share - Schedule of Earnings Per Share Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended							5 Months Ended	7 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 02, 2019	Dec. 31, 2019	Sep. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 02, 2019	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net income (loss)	$ (12.4)	$ (15.8)	$ (3.2)	$ (1.6)	$ (3.2)	$ (4.0)	$ 0.3	$ 1.9	$ (6.8)	$ (19.0)	$ (17.2)	$ (17.2)	$ (8.6)	$ 27.7
Income allocated to participating preferred shares										0.0		0.0	0.0	0.0
Net income (loss) attributable to common stockholders for basic and diluted EPS										$ (19.0)		$ (17.2)	$ (8.6)	$ 27.7
Basic weighted average common shares outstanding (shares)										995		55,392,201	995	995
Denominator adjustments for diluted EPS:
Assumed exercise of warrants										0		0	0	0
Assumed vesting of RSUs										0		0	0	0
Dilutive weighted average common shares outstanding (shares)										995		55,392,201	995	995
Earnings (loss) per share attributable to common stockholders:
Earnings (loss) per share attributable to common stockholders, basic (in usd per share)										$ (19,195.40)		$ (0.31)	$ (8,697.61)	$ 27,801.44
Earnings (loss) per share attributable to common stockholders, diluted (in usd per share)										$ (19,195.40)		$ (0.31)	$ (8,697.61)	$ 27,801.44