Debt - 2013 Issuances (Details)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2016 EUR (€)	Oct. 31, 2013 EUR (€) tranche	Jun. 30, 2012 EUR (€) tranche
Line of Credit Facility [Line Items]
Debt instrument, face amount			€ 450,000,000
Interest rate, stated percentage		3.45%	0.875%
Unsecured debt
Line of Credit Facility [Line Items]
Debt instrument, face amount				€ 355,000,000	€ 325,000,000
Number of tranches | tranche				3	3
Unsecured debt | 3.75% 2013 Private placement notes due 2033
Line of Credit Facility [Line Items]
Debt instrument, face amount				€ 100,000,000
Interest rate, stated percentage	3.75%	3.75%		3.75%
Unsecured debt | 3.15% 2013 Private placement notes due 2023
Line of Credit Facility [Line Items]
Debt instrument, face amount				€ 130,000,000
Interest rate, stated percentage	3.15%	3.15%		3.15%
Unsecured debt | 3.15% 2013 Private placement notes due 2023
Line of Credit Facility [Line Items]
Debt instrument, face amount				€ 125,000,000
Interest rate, stated percentage				3.15%