Summary of Significant Accounting Policies and New Accounting Pronouncements - Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expense of definite-life intangibles	$ 7	$ 7	$ 1
Amortization expense 2020	7
Amortization expense 2021	7
Amortization expense 2022	7
Amortization expense 2023	7
Amortization expense 2024	7
Amortization expense thereafter	$ 10
Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	8 years
Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	15 years