Loss Per Share (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	May 28, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from loss per shares (in shares)									287,326	446,821	0
Net loss attributable to common shareholders	$ (96,000,000)	$ (133,000,000)	$ (133,000,000)	$ (137,000,000)	$ (114,000,000)	$ (68,000,000)	$ (63,000,000)	$ (32,000,000)
Basic and diluted:
Net loss attributable to common shareholders	$ (96,000,000)	$ (133,000,000)	$ (133,000,000)	$ (137,000,000)	$ (114,000,000)	$ (68,000,000)	$ (63,000,000)	$ (32,000,000)
Basic: Weighted average number of shares outstanding (in millions) (in shares)									101,620,000	87,160,000	87,130,000
Diluted: Weighted-average number of shares outstanding, assuming dilution (in millions) (in shares)									101,620,000	87,160,000	87,130,000
Basic loss per share (in dollars per share)	$ (0.87)	$ (1.20)	$ (1.39)	$ (1.57)	$ (1.31)	$ (0.78)	$ (0.72)	$ (0.36)	$ (4.92)	$ (3.17)	$ (2.49)
Diluted loss per share (in dollars per share)	$ (0.87)	$ (1.20)	$ (1.39)	$ (1.57)	$ (1.31)	$ (0.78)	$ (0.72)	$ (0.36)	$ (4.92)	$ (3.17)	$ (2.49)
Anti-dilutive shares excluded from loss per shares (in shares)									287,326	446,821	0
Debt Conversion Converted Instrument, Potential Maximum, Number Of Shares Issued	9,277,305								9,277,305
Accumulated Deficit
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net loss attributable to common shareholders									$ (500,000,000)	$ (276,000,000)	$ (217,000,000)
Basic and diluted:
Net loss attributable to common shareholders									$ (500,000,000)	$ (276,000,000)	$ (217,000,000)
Convertible Debt Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from loss per shares (in shares)									5,515,548
Basic and diluted:
Anti-dilutive shares excluded from loss per shares (in shares)									5,515,548
4% Convertible Senior Notes Due 2024 | Convertible Notes Payable
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt instrument, conversion price	$ 22.3125								$ 22.3125			$ 22.3125
Basic and diluted:
Debt instrument, conversion price	$ 22.3125								$ 22.3125			$ 22.3125