Fair value measurement (Details) - USD ($) $ in Millions	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Assets:
Interest-bearing securities	$ 6,413		$ 7,304
Equity securities	492		831
Derivatives:
Total assets	7,347		8,400
Derivatives:
Contingent consideration obligations	310	$ 330	342	$ 48	$ 39	$ 33
Total liabilities	1,434		876
Foreign currency contracts [Member]
Derivatives:
Foreign currency and cross-currency swap contracts	413		183
Derivatives:
Foreign currency and cross-currency swap contracts	30		39
Cross-currency swap contracts [Member]
Derivatives:
Foreign currency and cross-currency swap contracts	29		66
Derivatives:
Foreign currency and cross-currency swap contracts	503		339
Interest rate swap contracts [Member]
Derivatives:
Interest rate swap contracts	0		16
Derivatives:
Interest rate swap contracts	591		156
Quoted prices in active markets for identical assets (Level 1) [Member]
Assets:
Equity securities	361		611
Derivatives:
Total assets	6,774		7,914
Derivatives:
Contingent consideration obligations	0		0
Total liabilities	0		0
Quoted prices in active markets for identical assets (Level 1) [Member] | Foreign currency contracts [Member]
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) [Member] | Cross-currency swap contracts [Member]
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) [Member] | Interest rate swap contracts [Member]
Derivatives:
Interest rate swap contracts	0		0
Derivatives:
Interest rate swap contracts	0		0
Significant other observable inputs (Level 2) [Member]
Assets:
Equity securities	0		0
Derivatives:
Total assets	442		266
Derivatives:
Contingent consideration obligations	0		0
Total liabilities	1,124		534
Significant other observable inputs (Level 2) [Member] | Foreign currency contracts [Member]
Derivatives:
Foreign currency and cross-currency swap contracts	413		183
Derivatives:
Foreign currency and cross-currency swap contracts	30		39
Significant other observable inputs (Level 2) [Member] | Cross-currency swap contracts [Member]
Derivatives:
Foreign currency and cross-currency swap contracts	29		66
Derivatives:
Foreign currency and cross-currency swap contracts	503		339
Significant other observable inputs (Level 2) [Member] | Interest rate swap contracts [Member]
Derivatives:
Interest rate swap contracts	0		16
Derivatives:
Interest rate swap contracts	591		156
Significant unobservable inputs (Level 3) [Member]
Assets:
Equity securities	131		220
Derivatives:
Total assets	131		220
Derivatives:
Contingent consideration obligations	310		342
Total liabilities	310		342
Significant unobservable inputs (Level 3) [Member] | Foreign currency contracts [Member]
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) [Member] | Cross-currency swap contracts [Member]
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) [Member] | Interest rate swap contracts [Member]
Derivatives:
Interest rate swap contracts	0		0
Derivatives:
Interest rate swap contracts	0		0
U.S. Treasury notes [Member]
Assets:
Interest-bearing securities	0		47
U.S. Treasury notes [Member] | Quoted prices in active markets for identical assets (Level 1) [Member]
Assets:
Interest-bearing securities	0		47
U.S. Treasury notes [Member] | Significant other observable inputs (Level 2) [Member]
Assets:
Interest-bearing securities	0		0
U.S. Treasury notes [Member] | Significant unobservable inputs (Level 3) [Member]
Assets:
Interest-bearing securities	0		0
U.S. Treasury bills [Member]
Assets:
Interest-bearing securities	1,980		1,400
U.S. Treasury bills [Member] | Quoted prices in active markets for identical assets (Level 1) [Member]
Assets:
Interest-bearing securities	1,980		1,400
U.S. Treasury bills [Member] | Significant other observable inputs (Level 2) [Member]
Assets:
Interest-bearing securities	0		0
U.S. Treasury bills [Member] | Significant unobservable inputs (Level 3) [Member]
Assets:
Interest-bearing securities	0		0
Money market mutual funds [Member]
Assets:
Interest-bearing securities	4,433		5,856
Money market mutual funds [Member] | Quoted prices in active markets for identical assets (Level 1) [Member]
Assets:
Interest-bearing securities	4,433		5,856
Money market mutual funds [Member] | Significant other observable inputs (Level 2) [Member]
Assets:
Interest-bearing securities	0		0
Money market mutual funds [Member] | Significant unobservable inputs (Level 3) [Member]
Assets:
Interest-bearing securities	0		0
Other short-term interest-bearing securities [Member]
Assets:
Interest-bearing securities	0		1
Other short-term interest-bearing securities [Member] | Quoted prices in active markets for identical assets (Level 1) [Member]
Assets:
Interest-bearing securities	0		0
Other short-term interest-bearing securities [Member] | Significant other observable inputs (Level 2) [Member]
Assets:
Interest-bearing securities	0		1
Other short-term interest-bearing securities [Member] | Significant unobservable inputs (Level 3) [Member]
Assets:
Interest-bearing securities	$ 0		$ 0