Fair Value of Financial Instruments (Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt securities:
Financial investments	$ 177	$ 291
Fair Value, Measurements, Recurring
Debt securities:
Financial investments	177	291
Fair Value, Measurements, Recurring | European government
Debt securities:
Financial investments	139	157
Fair Value, Measurements, Recurring | Corporate
Debt securities:
Financial investments	14	34
Fair Value, Measurements, Recurring | State owned enterprises and municipalities
Debt securities:
Financial investments	3	24
Fair Value, Measurements, Recurring | Swedish mortgage bonds
Debt securities:
Financial investments	21	19
Fair Value, Measurements, Recurring | Time deposits
Debt securities:
Financial investments	0	57
Fair Value, Measurements, Recurring | Level 1
Debt securities:
Financial investments	139	157
Fair Value, Measurements, Recurring | Level 1 | European government
Debt securities:
Financial investments	139	157
Fair Value, Measurements, Recurring | Level 1 | Corporate
Debt securities:
Financial investments	0	0
Fair Value, Measurements, Recurring | Level 1 | State owned enterprises and municipalities
Debt securities:
Financial investments	0	0
Fair Value, Measurements, Recurring | Level 1 | Swedish mortgage bonds
Debt securities:
Financial investments	0	0
Fair Value, Measurements, Recurring | Level 1 | Time deposits
Debt securities:
Financial investments	0	0
Fair Value, Measurements, Recurring | Level 2
Debt securities:
Financial investments	38	134
Fair Value, Measurements, Recurring | Level 2 | European government
Debt securities:
Financial investments	0	0
Fair Value, Measurements, Recurring | Level 2 | Corporate
Debt securities:
Financial investments	14	34
Fair Value, Measurements, Recurring | Level 2 | State owned enterprises and municipalities
Debt securities:
Financial investments	3	24
Fair Value, Measurements, Recurring | Level 2 | Swedish mortgage bonds
Debt securities:
Financial investments	21	19
Fair Value, Measurements, Recurring | Level 2 | Time deposits
Debt securities:
Financial investments	0	57
Fair Value, Measurements, Recurring | Level 3
Debt securities:
Financial investments	0	0
Fair Value, Measurements, Recurring | Level 3 | European government
Debt securities:
Financial investments	0	0
Fair Value, Measurements, Recurring | Level 3 | Corporate
Debt securities:
Financial investments	0	0
Fair Value, Measurements, Recurring | Level 3 | State owned enterprises and municipalities
Debt securities:
Financial investments	0	0
Fair Value, Measurements, Recurring | Level 3 | Swedish mortgage bonds
Debt securities:
Financial investments	0	0
Fair Value, Measurements, Recurring | Level 3 | Time deposits
Debt securities:
Financial investments	$ 0	$ 0