Fair Value of Financial Instruments (Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Debt securities:
Debt securities	$ 254	$ 291
European government
Debt securities:
Debt securities	149	157
Corporate
Debt securities:
Debt securities	52	34
State owned enterprises and municipalities
Debt securities:
Debt securities	35	24
Swedish mortgage bonds
Debt securities:
Debt securities	18	19
Time deposits
Debt securities:
Debt securities	0	57
Level 1
Debt securities:
Debt securities	149	157
Level 1 | European government
Debt securities:
Debt securities	149	157
Level 1 | Corporate
Debt securities:
Debt securities	0	0
Level 1 | State owned enterprises and municipalities
Debt securities:
Debt securities	0	0
Level 1 | Swedish mortgage bonds
Debt securities:
Debt securities	0	0
Level 1 | Time deposits
Debt securities:
Debt securities	0	0
Level 2
Debt securities:
Debt securities	105	134
Level 2 | European government
Debt securities:
Debt securities	0	0
Level 2 | Corporate
Debt securities:
Debt securities	52	34
Level 2 | State owned enterprises and municipalities
Debt securities:
Debt securities	35	24
Level 2 | Swedish mortgage bonds
Debt securities:
Debt securities	18	19
Level 2 | Time deposits
Debt securities:
Debt securities	0	57
Level 3
Debt securities:
Debt securities	0	0
Level 3 | European government
Debt securities:
Debt securities	0	0
Level 3 | Corporate
Debt securities:
Debt securities	0	0
Level 3 | State owned enterprises and municipalities
Debt securities:
Debt securities	0	0
Level 3 | Swedish mortgage bonds
Debt securities:
Debt securities	0	0
Level 3 | Time deposits
Debt securities:
Debt securities	$ 0	$ 0