Contingencies, Commitments and Guarantees (Contingencies - Narrative) (Details) $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2020 USD ($) Claims	Jun. 30, 2019 Claims	Dec. 31, 2019 Claims
Minimum
Loss Contingencies
Loss Contingency, Range of Possible Loss, Portion Not Accrued	$ 0
Maximum
Loss Contingencies
Loss Contingency, Range of Possible Loss, Portion Not Accrued	$ 200
Asbestos Related Claims
Loss Contingencies
Asbestos-Related Claims | Claims	1,121	1,705	3,187