Stock Compensation Plans (Details Textual) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Installment Y	Dec. 31, 2010	Dec. 31, 2009
Stock Compensation Plans (Textual) [Abstract]
Total compensation cost related to non-vested awards not yet recognized	$ 60
Weighted average period of compensation cost recognized (in years)	1.5
Condition for Options to become exercisable	over a three year period commencing one year from the date of grant, while certain other options become exercisable at the later of three years from the date of grant or upon specified market appreciation of the Company’s common shares.
Period commencing one year from date of grant	3 years
Period commencing from date of grant	3 years
Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value	$ 10.76	$ 0.00	$ 3.06
Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value	2	1	0
Restricted shares or units granted	3,400,000
Weighted average grant date fair value	$ 27.60	$ 35.83
Restricted shares or units outstanding	4,164,000	1,889,000
Share Based Compensation Arrangement by Share Based Payment Award Vesting Period Maximum	2 years
Number of Equal Installment of Deferred Unit Credited are Paid to Employee	3
Share based compensation arrangement by share based payment award discount from fair value	15% discount off of the beginning stock price plus the value of six month European call and put options
Weighted Average Grant Date fair value for restricted shares or units	$ 28.22
Expected annualized spot volatility minimum	35.80%		57.80%
Expected annualized spot volatility maximum	47.10%		57.80%
Risk-free spot rate minimum	0.10%		0.30%
Risk-free spot rate maximum	3.50%		4.20%
ISOP 2005 [Member]
Stock Compensation Plans (Textual) [Abstract]
Shares available for future issuance	14,652,180
ISOP 2010 [Member]
Stock Compensation Plans (Textual) [Abstract]
Maximum limit of shares awarded	18,000,000
Duration of the Incentive Stock Option Plan	10 years
Option's maximum terms in years	10 years
Maximum Limit of Shares Awarded to any individual employee under 2010 Stock Option Plan	2,000,000
Deferred Stock Unit Plan [Member]
Stock Compensation Plans (Textual) [Abstract]
Deferred Units credited	on or after January 1, 2010 (and any credited to senior executive officers hired on or after October 1, 2009) are paid in three equal installments after the first, second and third anniversaries of their grant date
Number of Award Types Under Deferred Stock Unit Plan	2
Restricted stock vesting period	3
Restricted Stock Unit Awards [Member]
Stock Compensation Plans (Textual) [Abstract]
Graded vesting attribution method	views one three-year grant with annual graded vesting as three separate sub-grants, each representing one third of the total number of awards granted. The first sub-grant vests over one year, the second sub-grant vests over two years and the third sub-grant vests over three years
Restricted shares or units granted	0	2,983
Restricted shares or units outstanding	5,319	6,812
Deferred Stock Unit payment criteria	Deferred Units credited to employees prior to January 1, 2010 (other than senior executive officers hired on or after October 1, 2009) are not paid until after two years from their grant date. Deferred Units credited on or after January 1, 2010 (and any credited to senior executive officers hired on or after October 1, 2009) are paid in three equal installments after the first, second and third anniversaries of their grant date
Performance Based Share Awards [Member]
Stock Compensation Plans (Textual) [Abstract]
Performance shares payable criteria	within a range of 0% to 200% of the number of shares initially granted based upon the attainment of specific performance goals achieved over a specified period, generally three years
Performance goals achievement period.	3 years
Fair value of shares vested based on estimated performance factors	20	13	8
Employee Stock [Member]
Stock Compensation Plans (Textual) [Abstract]
Discount rate on purchase of common stock under Employee Stock Purchase Plan	5.00%	5.00%	15.00%
Shares available for sale to eligible employees	15,400,000
Shares available for future issuance	6,472,280
Number of shares sold	768,380	729,598	2,557,893
Weighted average per share fair value of discount	$ 1.03	$ 1.24	$ 5.99
Net intrinsic value of discounts at purchase			$ 5
Restricted stock units, restricted stock and performance shares [Member] | ISOP 2010 [Member]
Stock Compensation Plans (Textual) [Abstract]
Maximum Limit of Shares Awarded to any individual employee under 2010 Stock Option Plan	500,000