Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2019

Dec. 31, 2018

Stockholders' Equity Attributable to Parent [Abstract]

Summary Of Common Stock Activity [Table Text Block]

The following table summarizes Common Stock activity during the periods presented below:

	Year Ended December 31, 2019		Year Ended December 31, 2018		April 2 through December 31, 2017
	(In millions)
Shares outstanding at the beginning of the period	110.4		105.2		70.9
Shares issued for preferred share conversions	—		25.5		33.8
Shares issued for warrant conversions	—		—		6.2
Shares issued for vested restricted stock units	1.5		1.1		0.1
Shares issued for disputed claims	—		0.1		—
Shares repurchased	(15.0	)	(21.5	)	(5.8	)
Shares outstanding at the end of the period	96.9		110.4		105.2

Summary of Preferred Stock Activity [Table Text Block]

The following table summarizes the Series A Convertible Preferred Stock activity during the periods presented below:

	Year Ended December 31, 2018		April 2 through December 31, 2017
	(In millions)
Shares outstanding at the beginning of the period	13.5		30.0
Shares converted to Common Stock	(13.5	)	(17.2	)
Shares issued for payable in-kind preferred stock dividends	—		0.7
Shares outstanding at the end of the period	—		13.5