Property and Equipment, Net - Additional Information (Details) - USD ($)	5 Months Ended	7 Months Ended	12 Months Ended
	Dec. 31, 2018	Jul. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Depreciation and amortization	$ 16,000,000	$ 31,000,000	$ 54,000,000	$ 56,000,000
Impairment of assets	$ 0			11,000,000
Software and Hardware
Property, Plant and Equipment [Line Items]
Impairment of assets			$ 3,000,000	10,000,000
Old Company Website
Property, Plant and Equipment [Line Items]
Impairment of assets				$ 1,000,000