New Accounting Standards New Accounting Standards (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of New Accounting Standard Current Expected Credit Losses	$ (12)	$ 0
Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of New Accounting Standard Current Expected Credit Losses	15
Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of New Accounting Standard Current Expected Credit Losses	$ 55