Debt of The Company (Details)	Dec. 31, 2015
3.950% Notes Due 2022
Debt Instrument [Line Items]
Interest rate (as a percent)	3.95%
3.625% notes due 2022
Debt Instrument [Line Items]
Interest rate (as a percent)	3.625%
3.400% Notes Due 2020
Debt Instrument [Line Items]
Interest rate (as a percent)	3.40%
4.750% Notes Due 2025
Debt Instrument [Line Items]
Interest rate (as a percent)	4.75%
Exchangeable senior debentures | 4.750% Notes Due 2023
Debt Instrument [Line Items]
Interest rate (as a percent)	4.75%
Senior Notes | 5.875% notes due 2020
Debt Instrument [Line Items]
Interest rate (as a percent)	5.875%
Senior Notes | 5.25% notes due 2021
Debt Instrument [Line Items]
Interest rate (as a percent)	5.25%
Senior Notes | 3.950% Notes Due 2022
Debt Instrument [Line Items]
Interest rate (as a percent)	3.95%
Senior Notes | 3.625% notes due 2022
Debt Instrument [Line Items]
Interest rate (as a percent)	3.625%
Senior Notes | 4.25% notes due 2025
Debt Instrument [Line Items]
Interest rate (as a percent)	4.25%
Senior Notes | 3.400% Notes Due 2020
Debt Instrument [Line Items]
Interest rate (as a percent)	3.40%
Senior Notes | 4.750% Notes Due 2025
Debt Instrument [Line Items]
Interest rate (as a percent)	4.75%