Employee Benefits - Defined Contribution (Details) - USD ($)	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 31, 2017	Oct. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, maximum annual contribution per employee			$ 18,500	$ 18,000
Defined contribution plan, maximum annual contribution per employee, percentage			100.00%
Defined contribution plan, employer matching contribution, percentage			4.00%
Defined contribution plan, cost	$ 7,000,000
All Other Defined Contribution
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost	1,000,000		$ 5,000,000
Cost of services and products
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost	1,000,000
Selling, general and administrative expense
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost	$ 5,000,000
Predecessor
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost		$ 30,000,000			$ 37,000,000
Predecessor | All Other Defined Contribution
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost		5,000,000			6,000,000
Predecessor | Cost of services and products
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost		4,000,000			5,000,000
Predecessor | Selling, general and administrative expense
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost		$ 26,000,000			$ 32,000,000