Income and Other Taxes - Reconciliation of Statutory Tax Rate to Effective Tax Rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	21.00%	21.00%	21.00%
Nondeductible expenses	(3.60%)	(1.90%)	4.10%
Effect of tax law changes	0.10%	3.10%	(10.50%)
Change in valuation allowance for deferred tax assets	(2.20%)	2.00%	9.90%
State taxes, net of federal benefit	0.30%	(0.60%)	5.50%
Audit and other tax return adjustments	(1.60%)	5.60%	1.40%
Tax-exempt income, credits and incentives	8.70%	4.50%	(5.90%)
Foreign rate differential adjusted for U.S. taxation of foreign profits	(0.10%)	(0.90%)	(2.60%)
Stock-based compensation	(0.60%)	(0.20%)	2.30%
Goodwill impairment	(22.00%)	(29.10%)	0.00%
Other	0.90%	0.10%	0.20%
Effective Income Tax Rate	0.90%	3.60%	25.40%
Income taxes to federal, foreign and state jurisdictions	$ 50	$ 61	$ 32