Debt (Details) $ in Thousands, € in Millions, £ in Millions			1 Months Ended		12 Months Ended
		May 31, 2017 USD ($)	Jul. 31, 2018 EUR (€)	Jul. 31, 2018 GBP (£)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2019 GBP (£) Interest / Debt Debt / EBITDA	Dec. 31, 2019 USD ($) Interest / Debt Debt / EBITDA	Oct. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Apr. 30, 2017 USD ($)
Schedule of long term debt [Abstract]
Long term debt						$ 689,782			$ 598,674
Less debt fees						(229)			(175)
Total long-term debt						689,553			598,499
Accounts receivable securitization program commitment amount									65,000	$ 65,000	$ 70,000	$ 60,000
Maximum borrowing capacity, secured loan									65,000			$ 60,000
Credit facility, borrowings outstanding						70,000			65,000
Proceeds from additional borrowings					$ 47,083	322,529	$ 231,174
Aggregate amounts of contractual maturities of long-term debt [Abstract]
Amounts due in 2020									128,300
Amounts due in 2021									14,600
Amounts due in 2022									118,300
Amounts due in 2023									151,200
Amounts due in 2024									83,200
Thereafter									102,900
Stand-by letters of credit outstanding						6,400			2,600
Short-term borrowings [Abstract]
Short-term borrowings						$ 20,046			$ 20,612
Weighted-average interest rates on short-term borrowings						3.24%		2.53%	2.53%
Minimum [Member]
Debt covenants [Abstract]
Interest coverage, actual | Interest / Debt								5.25	5.25
Interest coverage, required | Interest / Debt								2.00	2.00
Maximum [Member]
Debt covenants [Abstract]
Debt to EBITDA, actual | Debt / EBITDA	[1]							2.86	2.86
Debt to EBITDA, required | Debt / EBITDA	[1]							3.50	3.50
LIBOR [Member]
Schedule of long term debt [Abstract]
Interest rate					0.70%
Revolving Credit Facility [Member]
Schedule of long term debt [Abstract]
Long term debt						$ 142,061			$ 134,393
Average interest rate						2.08%		1.44%	1.44%
Maximum borrowing capacity, secured loan		$ 350,000
Proceeds from additional borrowings			€ 45	£ 50
Long term debt additional disclosures [Abstract]
Remaining borrowing capacity									$ 319,500
Revolving Credit Facility [Member] | Minimum [Member]
Schedule of long term debt [Abstract]
Maturity date					Nov. 30, 2020
Revolving Credit Facility [Member] | Maximum [Member]
Schedule of long term debt [Abstract]
Maturity date					May 31, 2022
Other Line of Credit Facility [Member]
Long term debt additional disclosures [Abstract]
Remaining borrowing capacity									58,100
U.S. Credit Facilities [Member]
Short-term borrowings [Abstract]
Short-term borrowings						$ 19,768			20,280
Loans of Foreign Subsidiaries [Member]
Short-term borrowings [Abstract]
Short-term borrowings						278			332
3.66% Senior Notes due November 2023 [Member]
Schedule of long term debt [Abstract]
Long term debt						75,000			$ 75,000
Interest rate, stated percentage								3.66%	3.66%
Maturity date					Nov. 30, 2023
3.65% Senior Notes due May 2024 [Member]
Schedule of long term debt [Abstract]
Long term debt						27,000			$ 27,000
Interest rate, stated percentage								3.65%	3.65%
Maturity date					May 31, 2024
4.19% Senior Notes due November 2025 [Member]
Schedule of long term debt [Abstract]
Long term debt						25,000			$ 25,000
Interest rate, stated percentage								4.19%	4.19%
Maturity date					Nov. 30, 2025
Debt instrument amount									$ 25,000
1.27% Euro-denominated Senior Notes due May 2024 [Member]
Schedule of long term debt [Abstract]
Long term debt						57,333			$ 56,066
Interest rate, stated percentage								1.27%	1.27%
Maturity date					May 31, 2024
1.71% Euro-denominated Senior Notes due May 2027 [Member]
Schedule of long term debt [Abstract]
Long term debt						45,866			$ 44,853
Interest rate, stated percentage								1.71%	1.71%
Maturity date					May 31, 2027
3.06% Euro-denominated Senior Notes due November 2023 [Member]
Schedule of long term debt [Abstract]
Long term debt						43,856			$ 42,887
Interest rate, stated percentage								3.06%	3.06%
Maturity date					Nov. 30, 2023
1.85% Euro-denominated Senior Notes due November 2022 [Member]
Schedule of long term debt [Abstract]
Long term debt						76,662			$ 74,968
Interest rate, stated percentage								1.85%	1.85%
Maturity date					Nov. 30, 2022
2.53% British Pound-denominated Notes due November 2023 [Member]
Schedule of long term debt [Abstract]
Long term debt						31,884			$ 33,143
Interest rate, stated percentage								2.53%	2.53%
Maturity date					Nov. 30, 2023
Debt instrument amount | £								£ 25
2.76% British Pound-denominated Notes due November 2025 [Member]
Schedule of long term debt [Abstract]
Long term debt						31,884			$ 33,143
Interest rate, stated percentage								2.76%	2.76%
Maturity date					Nov. 30, 2025
Debt instrument amount | £								£ 25
Term Loan [Member]
Schedule of long term debt [Abstract]
Long term debt						$ 132,313			$ 51,438
Average interest rate						3.48%		3.83%	3.83%
Maximum borrowing capacity, secured loan		145,000											$ 115,000
Credit facility increased amount		30,000
Credit facility, borrowings outstanding		$ 51,400
Aggregate amounts of contractual maturities of long-term debt [Abstract]
Amounts due in 2020									$ 12,800
Term Loan [Member] | Euro Revolving Credit Facility [Member]
Aggregate amounts of contractual maturities of long-term debt [Abstract]
Amounts due in 2020									50,500
Various Other Notes [Member]
Schedule of long term debt [Abstract]
Long term debt						$ 923			$ 783
Private Placement Notes [Member]
Schedule of long term debt [Abstract]
Debt instrument amount | £								£ 50

[1] Debt to EBITDA is defined in the Company’s debt covenants as total funded debt divided by the Company’s consolidated operating income excluding non-operating gains and losses and depreciation and amortization.