Financial Instruments - Interest Rate Risk (Details) - Senior Notes	Sep. 30, 2021
3.250% 2013 senior notes due 2023
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Interest rate percentage	3.25%
4.500% 2015 senior notes due 2025
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Interest rate percentage	4.50%
Senior notes due 2018
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Interest rate percentage	3.90%