v3.26.1
Common stock (Detail)
 6 Months Ended
Jun. 30, 2026
shares
Class A [Member]  
Class of Stock [Line Items]  
Shares issued, beginning balance 592,175
Treasury shares, beginning balance (76,340)
Shares outstanding, beginning balance 515,835
Conversions of Class A to Class B common stock (14,223)
Conversions of Class A to Class B common stock, Outstanding (14,223)
Treasury stock acquired (511)
Shares issued, ending balance 577,952
Treasury shares, ending balance (76,851)
Shares outstanding, ending balance 501,101
Class B [Member]  
Class of Stock [Line Items]  
Shares issued, beginning balance 1,598,881,852
Treasury shares, beginning balance (215,299,213)
Shares outstanding, beginning balance 1,383,582,639
Conversions of Class A to Class B common stock 21,334,500
Conversions of Class A to Class B common stock, Outstanding 21,334,500
Treasury stock acquired (9,029,655)
Shares issued, ending balance 1,620,216,352
Treasury shares, ending balance (224,328,868)
Shares outstanding, ending balance 1,395,887,484