Taxes on Income - Temporary Differences (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Employee compensation	$ 64	$ 58
Accrued expenses	41	35
Postretirement benefits	12	27
Unearned revenue	28	28
Loss carryforwards	217	155
Lease liabilities	186	199
Other	53	25
Total deferred tax assets	601	527
Deferred tax liabilities:
Goodwill and intangible assets	(347)	(318)
Right of use asset	138	194
Fixed assets	(7)	0
Total deferred tax liabilities	(492)	(512)
Net deferred income tax asset before valuation allowance	109	15
Valuation allowance	(219)	(163)
Net deferred income tax (liability) asset	(110)	(148)
Reported as:
Non-current deferred tax assets	67	52
Non-current deferred tax liabilities	(177)	(200)
Net deferred income tax (liability) asset	$ (110)	$ (148)