Other Intangible Assets Level 4 - Expected Pre-tax Amortization Expense (Details) $ in Millions	Mar. 31, 2019 USD ($)
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	$ 5
Finite-Lived Intangible Assets, Amortization Expense, Year Two	6
Finite-Lived Intangible Assets, Amortization Expense, Year Three	6
Finite-Lived Intangible Assets, Amortization Expense, Year Four	6
Finite-Lived Intangible Assets, Amortization Expense, Year Five	$ 1