Financial Instruments - Narrative (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2020 EUR (€)	Jun. 30, 2020 USD ($)	Jun. 30, 2020 EUR (€)	Jan. 01, 2020 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net change in allowance for credit losses	$ 22,200	$ 9,900
Retained earnings	$ 452,932	451,725
Line of credit facility, cost expressed as a percentage of extended amount	0.025%
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Marketable securities	$ 23,416	$ 0
Investments [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Marketable securities	$ 20,000			$ 23,400	€ 20,000,000.0
Interest rate percentage	0.75%		0.75%	0.25%	0.25%
RCF | Amended RCF Through March 2022 | Revolving credit facility
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 410,000		€ 350,000,000
RCF | Amended RCF To The End Of March 2022 Through March 2023 | Revolving credit facility
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 344,000		€ 294,000,000
Cumulative Effect, Period Of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings						$ 3,500