Share-Based Compensation (Details Textuals) (USD $)	12 Months Ended
	Dec. 31, 2012 years	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan, Shares	6,000,000
Shares purchased under the ESPP plans	300,000	200,000	200,000
Share-Based Compensation Textuals [Abstract]
Total shares of common stock available for grant	14,000,000
Common stock available for grant	11,800,000
Unrecognized compensation cost related to nonvested awards net of tax Total	$ 29,600,000
Unrecognized compensation cost period for recognition, years	3.75
Unrecognized compensation cost period for recognition, weighted-average, years	0.8
Total intrinsic value of options exercised	4,200,000	10,300,000	53,700,000
Goals to be achieved under Performance units awards based on stock price performance, percentage	50.00%
Goals to be achieved under Performance units awards based on a return on capital target, percentage	50.00%
Maximum employee Contribution to employee stock purchase plans based on compensation, percentage	15.00%
Maximum employee Contribution to employee stock purchase plans based on compensation, amount	25,000
Common stock discount under employee stock purchase plans	15.00%
Employee Stock Purchase Plans,Fair value estimation	estimated by adding the fair value of 0.15 of one share of stock to the fair value of 0.85 of an option on one share of stock
Total fair value of restricted stock awards granted	44,400,000	36,900,000	23,300,000
Total fair value of restricted stock awards vested	19,900,000	50,000,000	20,500,000
U.S Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan, Shares	5,000,000
Australian Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan, Shares	1,000,000
Deferred Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of deferred stock units	after one year
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of performance units	after three years of service
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of performance units	Stock options generally vest in one-third increments over a period of three years or cliff vest after three years, and expire after 10 years from the date of grant
Performance unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of performance units	3 years
Number of outstanding units vested	117,382
Aggregate intrinsic value	$ 1,100,000
Conversion price per share	$ 26.63