Annual report pursuant to Section 13 and 15(d)

CONSOLIDATED BALANCE SHEETS (Parenthetical)

v3.20.4
CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Treasury stock, shares 400,000 400,000    
Common Stock | Common Class A [Member]        
Common stock, shares issued 147,000,000 156,000,000 163,000,000 173,000,000
Common Stock | Common Class B [Member]        
Common stock, shares issued 718,000,000 701,000,000 696,000,000 687,000,000