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Earnings Per Share (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 15, 2018
Unvested Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (shares)	7.8	6.2	7.5	6.6
Warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (shares)				10.8
Convertible Senior Notes Due June 2018 \| Convertible notes payable
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Principal					$ 316.3
Interest rate					2.75%