Fair value measurement (Details) - USD ($) $ in Millions	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Assets:
Interest-bearing securities	$ 10,921		$ 7,304
Other investments	135		0
Equity securities	767		831
Derivatives:
Total assets	12,468		8,400
Derivatives:
Contingent consideration obligations	302	$ 310	342	$ 35	$ 48	$ 33
Total liabilities	1,888		876
Foreign currency contracts
Derivatives:
Foreign currency and cross-currency swap contracts	639		183
Derivatives:
Foreign currency and cross-currency swap contracts	22		39
Cross-currency swap contracts
Derivatives:
Foreign currency and cross-currency swap contracts	6		66
Derivatives:
Foreign currency and cross-currency swap contracts	754		339
Interest rate swap contracts
Derivatives:
Interest rate swap contracts	0		16
Derivatives:
Interest rate swap contracts	810		156
Quoted prices in active markets for identical assets (Level 1)
Assets:
Other investments	0		0
Equity securities	385		611
Derivatives:
Total assets	11,306		7,914
Derivatives:
Contingent consideration obligations	0		0
Total liabilities	0		0
Quoted prices in active markets for identical assets (Level 1) | Foreign currency contracts
Derivatives:
Foreign currency and cross-currency swap contracts	0		0
Derivatives:
Foreign currency and cross-currency swap contracts	0		0
Quoted prices in active markets for identical assets (Level 1) | Cross-currency swap contracts
Derivatives:
Foreign currency and cross-currency swap contracts	0		0
Derivatives:
Foreign currency and cross-currency swap contracts	0		0
Quoted prices in active markets for identical assets (Level 1) | Interest rate swap contracts
Derivatives:
Interest rate swap contracts	0		0
Derivatives:
Interest rate swap contracts	0		0
Significant other observable inputs (Level 2)
Assets:
Other investments	135		0
Equity securities	0		0
Derivatives:
Total assets	780		266
Derivatives:
Contingent consideration obligations	0		0
Total liabilities	1,586		534
Significant other observable inputs (Level 2) | Foreign currency contracts
Derivatives:
Foreign currency and cross-currency swap contracts	639		183
Derivatives:
Foreign currency and cross-currency swap contracts	22		39
Significant other observable inputs (Level 2) | Cross-currency swap contracts
Derivatives:
Foreign currency and cross-currency swap contracts	6		66
Derivatives:
Foreign currency and cross-currency swap contracts	754		339
Significant other observable inputs (Level 2) | Interest rate swap contracts
Derivatives:
Interest rate swap contracts	0		16
Derivatives:
Interest rate swap contracts	810		156
Significant unobservable inputs (Level 3)
Assets:
Other investments	0		0
Equity securities	382		220
Derivatives:
Total assets	382		220
Derivatives:
Contingent consideration obligations	302		342
Total liabilities	302		342
Significant unobservable inputs (Level 3) | Foreign currency contracts
Derivatives:
Foreign currency and cross-currency swap contracts	0		0
Derivatives:
Foreign currency and cross-currency swap contracts	0		0
Significant unobservable inputs (Level 3) | Cross-currency swap contracts
Derivatives:
Foreign currency and cross-currency swap contracts	0		0
Derivatives:
Foreign currency and cross-currency swap contracts	0		0
Significant unobservable inputs (Level 3) | Interest rate swap contracts
Derivatives:
Interest rate swap contracts	0		0
Derivatives:
Interest rate swap contracts	0		0
U.S. Treasury notes
Assets:
Interest-bearing securities	0		47
U.S. Treasury notes | Quoted prices in active markets for identical assets (Level 1)
Assets:
Interest-bearing securities	0		47
U.S. Treasury notes | Significant other observable inputs (Level 2)
Assets:
Interest-bearing securities	0		0
U.S. Treasury notes | Significant unobservable inputs (Level 3)
Assets:
Interest-bearing securities	0		0
U.S. Treasury bills
Assets:
Interest-bearing securities	1,976		1,400
U.S. Treasury bills | Quoted prices in active markets for identical assets (Level 1)
Assets:
Interest-bearing securities	1,976		1,400
U.S. Treasury bills | Significant other observable inputs (Level 2)
Assets:
Interest-bearing securities	0		0
U.S. Treasury bills | Significant unobservable inputs (Level 3)
Assets:
Interest-bearing securities	0		0
Money market mutual funds
Assets:
Interest-bearing securities	8,945		5,856
Money market mutual funds | Quoted prices in active markets for identical assets (Level 1)
Assets:
Interest-bearing securities	8,945		5,856
Money market mutual funds | Significant other observable inputs (Level 2)
Assets:
Interest-bearing securities	0		0
Money market mutual funds | Significant unobservable inputs (Level 3)
Assets:
Interest-bearing securities	0		0
Other short-term interest-bearing securities
Assets:
Interest-bearing securities	0		1
Other short-term interest-bearing securities | Quoted prices in active markets for identical assets (Level 1)
Assets:
Interest-bearing securities	0		0
Other short-term interest-bearing securities | Significant other observable inputs (Level 2)
Assets:
Interest-bearing securities	0		1
Other short-term interest-bearing securities | Significant unobservable inputs (Level 3)
Assets:
Interest-bearing securities	$ 0		$ 0