Income Taxes - Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets
Net operating loss carryforward - US	$ 15	$ 371
Net operating loss carryforward - Non-US	150	178
Market value difference of loan portfolio	741	310
Accruals	86	115
Tax credits	466	839
Other	282	185
Total deferred tax assets before valuation allowance	1,740	1,998
Less: valuation allowance	(291)	(279)
Total deferred tax assets	1,449	1,719
Deferred tax liabilities
Depreciable assets	2,038	2,177
Deferred acquisition costs	109	123
Other	160	152
Total deferred tax liabilities	2,307	2,452
Net deferred tax liability	(858)	$ (733)
Tax Year 2042 [Member]
Deferred tax assets
Net operating loss carryforward - US	15
Tax Year 2040 [Member]
Deferred tax assets
Net operating loss carryforward - Non-US	125
Tax credits	466
Expiring Indefinitely [Member]
Deferred tax assets
Net operating loss carryforward - Non-US	$ 25