Investments (Operating Leases - Narrative) (Details) $ in Millions	Dec. 31, 2020 USD ($)
Investments, All Other Investments [Abstract]
Operating Leases, Future Minimum Payments Receivable, Current	$ 331
Operating Leases, Future Minimum Payments Receivable, in Two Years	268
Operating Leases, Future Minimum Payments Receivable, in Three Years	230
Operating Leases, Future Minimum Payments Receivable, in Four Years	200
Operating Leases, Future Minimum Payments Receivable, in Five Years	180
Operating Leases, Future Minimum Payments Receivable, Thereafter	1,200
Operating Leases, Future Minimum Payments Receivable	$ 2,400