Income taxes - Reconciliation of Effective Income Tax Rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
U.S. Federal Statutory Tax rate	$ 1,009	$ 990	$ 843
State and Local Income Taxes, Net of Federal Income Tax Effect	71	47	38
Effects of changes in tax laws or rates enacted in current period	3	0	0
Effect of Cross-Border Tax Laws	0	0	0
Nondeductible items		16
Tax credits	(12)	(15)	(19)
Changes in valuation allowances	0	0	0
Non-taxable or Nondeductible items	(13)		(40)
Changes in Unrecognized Tax Benefits	39	60	87
Effective income tax rate	$ 1,041	$ 1,085	$ 925
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal Statutory Tax rate	21.00%	21.00%	21.00%
State and Local Income Taxes, Net of Federal Income Tax Effect	1.50%	1.00%	1.00%
Effects of changes in tax laws or rates enacted in current period	0.10%	0.00%	0.00%
Effect of Cross-Border Tax Laws	0.00%	0.00%	0.00%
Nondeductible items		0.30%
Tax credits	(0.30%)	(0.30%)	(0.50%)
Changes in valuation allowances	0.00%
Non-taxable or Nondeductible items	(0.30%)		(1.00%)
Changes in Unrecognized Tax Benefits	0.80%	1.30%	2.20%
Effective income tax rate	22.00%	23.00%	23.00%
Ireland
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Effects of changes in tax laws or rates enacted in current period	$ (62)	$ (30)	$ (26)
Nondeductible items	50	67	48
Other	$ 13	$ (9)	$ (10)
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Effective income tax rate reconciliation, foreign income tax rate differential, percent	(1.30%)	(0.60%)	(0.70%)
Nondeductible items	1.00%	1.40%	1.20%
Other	0.30%	(0.20%)	(0.30%)
Malta
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Other	$ 41	$ 52	$ 39
Tax credits	(234)	(281)	(259)
Changes in valuation allowances	$ 149	$ 174	$ 166
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Other	0.90%	1.10%	1.00%
Tax credits	(4.90%)	(6.00%)	(6.50%)
Changes in valuation allowances	3.10%	3.70%	4.10%
Philippines
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Other	$ 12	$ 5	$ (8)
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Other	0.30%	0.10%	(0.20%)
Philippines | Goodwill
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Nondeductible impairment of goodwill	$ 0	$ 0	$ 74
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Nondeductible impairment of goodwill	0.00%	0.00%	1.80%
Poland
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Effects of changes in tax laws or rates enacted in current period	$ 2	$ 21	$ 3
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Effective income tax rate reconciliation, foreign income tax rate differential, percent	0.00%	0.50%	0.10%
Other foreign jurisdictions
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Effects of changes in tax laws or rates enacted in current period	$ (27)	$ (12)	$ (11)
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Effective income tax rate reconciliation, foreign income tax rate differential, percent	(0.60%)	(0.30%)	(0.30%)