Taxes on Income (Temporary Differences That Created Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Operating lease liabilities	$ 159
Employee compensation, severance, and benefits	154	$ 132
State and local taxes	22	21
Reserves and allowances	14	13
Net operating loss carryforwards	6	5
Net unrealized loss on available for sale securities	0	79
Facilities lease commitments	0	12
Other	0	6
Total deferred tax assets	355	268
Valuation allowance	(3)	(3)
Deferred tax assets — net of valuation allowance	352	265
Deferred tax liabilities:
Operating lease ROU assets	(146)
Depreciation and amortization	(113)	(108)
Capitalized internal-use software development costs	(97)	(98)
Capitalized contract costs	(68)	(60)
Net unrealized gain on available for sale securities	(28)	0
Other	(10)	0
Total deferred tax liabilities	(462)	(266)
Deferred tax asset/(liability) — net	$ (110)	$ (1)