Other Intangible Assets (Summary of Future Amortization Expense) (Details) - USD ($) $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended
	Sep. 30, 2017	Aug. 31, 2017	Sep. 30, 2016	Aug. 31, 2017	Sep. 30, 2016
Continuing Operations [Member]
Finite-Lived Intangible Assets [Line Items]
Pre-tax amortization expense, 2017	$ 512
Pre-tax amortization expense, 2018	1,096
Pre-tax amortization expense, 2019	1,090
Pre-tax amortization expense, 2020	1,080
Pre-tax amortization expense, 2021	1,067
Pre-tax amortization expense, 2022	1,060
Successor
Finite-Lived Intangible Assets [Line Items]
Aggregate pre-tax amortization expense - continuing operations	89
Successor | Continuing Operations [Member]
Finite-Lived Intangible Assets [Line Items]
Aggregate pre-tax amortization expense - continuing operations	$ 89
Predecessor | Continuing Operations [Member]
Finite-Lived Intangible Assets [Line Items]
Aggregate pre-tax amortization expense - continuing operations		$ 31	$ 46	$ 139	$ 272