Shareholders' Equity (Narrative) (Details) (USD $)	6 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized	1,000,000,000
Common stock, no par value (in dollars per share)	$ 0
Preferred stock, shares authorized	500,000
Preferred stock, no par value (in dollars per share)	$ 0
Treasury stock, shares	57,500,000		57,500,000	40,300,000
Treasury stock recorded at cost as a reduction of common stock (in dollars)	$ 1,600,000,000		$ 1,600,000,000	$ 1,100,000,000
Total compensation expense for option grants, Restricted Stock Awards and PSU's	31,000,000	34,000,000	48,000,000	47,000,000	45,000,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration, number of years after grant date	10 years
The weighted-average remaining contractual term of options outstanding	6 years
The weighted-average remaining contractual term of options exercisable	5 years
The aggregate intrinsic value of options outstanding (in dollars)	25,000,000
The aggregate intrinsic value of options exercisable (in dollars)	20,000,000
The weighted-average grant-date fair values of options granted (in dollars per share)	$ 5.89		$ 6.98	$ 8.82	$ 8.50
The total intrinsic values of options exercised (in dollars)	1,000,000		5,000,000	21,000,000	11,000,000
Cash proceeds received from options exercised (in dollars)	2,000,000		7,000,000	21,000,000	11,000,000
Total unrecognized compensation expense	21,000,000
Period during which unrecognized compensation expense is expected to be recognized	5 years
Amounts to be recognized as compensation expense during the next fiscal year	8,000,000
Amounts to be recognized as compensation expense during the year following the next fiscal year	6,000,000
Amounts to be recognized as compensation expense during the second year following the next fiscal year	4,000,000
Amounts to be recognized as compensation expense during the third year following the next fiscal year	2,000,000
Amounts to be recognized as compensation expense during the fourth year following the next fiscal year	1,000,000
Restricted Stock Awards And PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares or units granted as Restricted Stock Awards and PSUs (in shares)	1,319,000		1,249,000	1,100,000	1,000,000
Total unrecognized compensation expense	37,000,000
Period during which unrecognized compensation expense is expected to be recognized	3 years
Amounts to be recognized as compensation expense during the next fiscal year	20,000,000
Amounts to be recognized as compensation expense during the year following the next fiscal year	12,000,000
Amounts to be recognized as compensation expense during the second year following the next fiscal year	5,000,000
Weighted average grant-date fair value of Restricted Stock Awards and PSU's, Granted (in dollars per share)	$ 26.34		$ 26.75	$ 32.19	$ 26.55
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Total fair value of Restricted Stock Awards vested during the period	$ 17,000,000
Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
2009 Incentive Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grants (in shares)	20,800,000
Minimum [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	5 years
Maximum [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	9 years