Computation of Basic and Diluted Net Income Per Share (Detail) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	7 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Numerator
Allocation of undistributed earnings-continuing operations		$ 10,788	$ 9,737	$ 8,505
Allocation of undistributed earnings-discontinued operations	(51)	(51)	0	0
Total		10,737	9,737	8,505
Denominator
Continuing operations		$ 32.97	$ 30.17	$ 26.69
Discontinued operations		$ (0.16)	$ 0.00	$ 0.00
Basic net income per share		$ 32.81	$ 30.17	$ 26.69
Numerator
Allocation of undistributed earnings for basic computation-continuing operations		10,788	9,737	8,505
Allocation of undistributed earnings for basic computation-discontinued operations	(51)	(51)	0	0
Weighted-average effect of dilutive securities
Continuing operations		$ 32.46	$ 29.76	$ 26.31
Discontinued operations		$ (0.15)	$ 0.00	$ 0.00
Diluted net income per share		$ 32.31	$ 29.76	$ 26.31
Class A Common Stock
Numerator
Allocation of undistributed earnings-continuing operations		8,641	7,658	6,569
Allocation of undistributed earnings-discontinued operations		(41)	0	0
Total		8,600	7,658	6,569
Denominator
Weighted-average common shares outstanding		262,078	253,862	246,168
Number of shares used in per share computation		262,078	253,862	246,168
Continuing operations		$ 32.97	$ 30.17	$ 26.69
Discontinued operations		$ (0.16)	$ 0.00	$ 0.00
Basic net income per share		$ 32.81	$ 30.17	$ 26.69
Numerator
Allocation of undistributed earnings for basic computation-continuing operations		8,641	7,658	6,569
Allocation of undistributed earnings for basic computation-discontinued operations		(41)	0	0
Denominator
Number of shares used in basic computation		262,078	253,862	246,168
Weighted-average effect of dilutive securities
Conversion of Class B to Class A common shares outstanding		65,135	68,916	72,534
Employee stock options, including warrants issued under Transferable Stock Option program		2,944	2,958	3,410
Restricted stock units		2,148	1,478	1,139
Number of shares used in per share computation		332,305	327,214	323,251
Continuing operations		$ 32.46	$ 29.76	$ 26.31
Discontinued operations		$ (0.15)	$ 0.00	$ 0.00
Diluted net income per share		$ 32.31	$ 29.76	$ 26.31
Class A Common Stock | Continuing Operations
Numerator
Reallocation of undistributed earnings as a result of conversion of Class B to Class A shares		2,147	2,079	1,936
Reallocation of undistributed earnings to Class B shares		0	0	0
Allocation of undistributed earnings		10,788	9,737	8,505
Class A Common Stock | Discontinued Operations
Numerator
Reallocation of undistributed earnings as a result of conversion of Class B to Class A shares		(10)	0	0
Reallocation of undistributed earnings to Class B shares		0	0	0
Allocation of undistributed earnings		(51)	0	0
Class B Common Stock
Numerator
Allocation of undistributed earnings-continuing operations		2,147	2,079	1,936
Allocation of undistributed earnings-discontinued operations		(10)	0	0
Total		2,137	2,079	1,936
Denominator
Weighted-average common shares outstanding		65,135	68,916	72,534
Number of shares used in per share computation		65,135	68,916	72,534
Continuing operations		$ 32.97	$ 30.17	$ 26.69
Discontinued operations		$ (0.16)	$ 0.00	$ 0.00
Basic net income per share		$ 32.81	$ 30.17	$ 26.69
Numerator
Allocation of undistributed earnings for basic computation-continuing operations		2,147	2,079	1,936
Allocation of undistributed earnings for basic computation-discontinued operations		(10)	0	0
Denominator
Number of shares used in basic computation		65,135	68,916	72,534
Weighted-average effect of dilutive securities
Conversion of Class B to Class A common shares outstanding		0	0	0
Employee stock options, including warrants issued under Transferable Stock Option program		34	46	71
Restricted stock units		0	0	0
Number of shares used in per share computation		65,169	68,962	72,605
Continuing operations		$ 32.46	$ 29.76	$ 26.31
Discontinued operations		$ (0.15)	$ 0.00	$ 0.00
Diluted net income per share		$ 32.31	$ 29.76	$ 26.31
Class B Common Stock | Continuing Operations
Numerator
Reallocation of undistributed earnings as a result of conversion of Class B to Class A shares		0	0	0
Reallocation of undistributed earnings to Class B shares		(31)	(27)	(26)
Allocation of undistributed earnings		2,116	2,052	1,910
Class B Common Stock | Discontinued Operations
Numerator
Reallocation of undistributed earnings as a result of conversion of Class B to Class A shares		0	0	0
Reallocation of undistributed earnings to Class B shares		0	0	0
Allocation of undistributed earnings		$ (10)	$ 0	$ 0