Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Denominator
Basic net income per share (in dollars per share)	$ 9.96	$ 9.58
Weighted-average effect of dilutive securities
Diluted net income per share (in dollars per share)	$ 9.87	$ 9.50
Class A Common Stock
Numerator
Allocation of undistributed earnings	$ 2,990	$ 2,865
Denominator
Number of shares used in basic computation (shares)	300,249	299,042
Basic net income per share (in dollars per share)	$ 9.96	$ 9.58
Numerator
Allocation of undistributed earnings for basic computation	$ 2,990	$ 2,865
Reallocation of undistributed earnings as a result of conversion of Class B to Class A shares	462	446
Reallocation of undistributed earnings	(27)	(23)
Allocation of undistributed earnings	$ 3,425	$ 3,288
Denominator
Number of shares used in basic computation (shares)	300,249	299,042
Weighted-average effect of dilutive securities
Conversion of Class B to Class A common shares outstanding (shares)	46,424	46,582
Number of shares used in per share computation (shares)	346,853	346,134
Diluted net income per share (in dollars per share)	$ 9.87	$ 9.50
Class A Common Stock \| Restricted stock units and other contingently issuable shares
Weighted-average effect of dilutive securities
Restricted stock units and other contingently issuable shares (shares)	180	510
Class B Common Stock
Numerator
Allocation of undistributed earnings	$ 462	$ 446
Denominator
Number of shares used in basic computation (shares)	46,424	46,582
Basic net income per share (in dollars per share)	$ 9.96	$ 9.58
Numerator
Allocation of undistributed earnings for basic computation	$ 462	$ 446
Reallocation of undistributed earnings as a result of conversion of Class B to Class A shares	0	0
Reallocation of undistributed earnings	(4)	(4)
Allocation of undistributed earnings	$ 458	$ 442
Denominator
Number of shares used in basic computation (shares)	46,424	46,582
Weighted-average effect of dilutive securities
Conversion of Class B to Class A common shares outstanding (shares)	0	0
Number of shares used in per share computation (shares)	46,424	46,582
Diluted net income per share (in dollars per share)	$ 9.87	$ 9.50
Class B Common Stock \| Restricted stock units and other contingently issuable shares
Weighted-average effect of dilutive securities
Restricted stock units and other contingently issuable shares (shares)	0	0
Class C Capital Stock
Numerator
Allocation of undistributed earnings	$ 3,384	$ 3,346
Denominator
Number of shares used in basic computation (shares)	339,792	349,245
Basic net income per share (in dollars per share)	$ 9.96	$ 9.58
Numerator
Allocation of undistributed earnings for basic computation	$ 3,384	$ 3,346
Reallocation of undistributed earnings as a result of conversion of Class B to Class A shares	0	0
Reallocation of undistributed earnings	27	23
Allocation of undistributed earnings	$ 3,411	$ 3,369
Denominator
Number of shares used in basic computation (shares)	339,792	349,245
Weighted-average effect of dilutive securities
Conversion of Class B to Class A common shares outstanding (shares)	0	0
Number of shares used in per share computation (shares)	345,414	354,745
Diluted net income per share (in dollars per share)	$ 9.87	$ 9.50
Class C Capital Stock \| Restricted stock units and other contingently issuable shares
Weighted-average effect of dilutive securities
Restricted stock units and other contingently issuable shares (shares)	5,622	5,500

Dilutive impact on our earnings per share for the period as a result of conversion of Class B to Class A common stock.

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