Debt (Details texture) - USD ($) $ in Thousands		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 650,000
Net proceeds from credit facility and long-term debt, including current portion		175,000	$ 723,054
Repayments of credit facility		6,135	$ 378,095
Letters of Credit Outstanding, Amount		$ 10,800
Senior unsecured notes, interest rate		3.125%
Line of Credit Facility, Option To Increase Maximum Borrowing Capacity		$ 200,000
Long-term Debt, Gross		$ 425,000
Minimum
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.00%
Line of Credit Facility, Commitment Fee Percentage		0.125%
Maximum
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.375%
Line of Credit Facility, Commitment Fee Percentage		0.20%
United States of America, Dollars
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate During Period		1.683%
Swedish Kronor
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate During Period		1.444%
Term Loan Facility
Line of Credit Facility [Line Items]
Net proceeds from credit facility and long-term debt, including current portion		$ 100,000
Term Loan Facility | United States of America, Dollars
Line of Credit Facility [Line Items]
Senior unsecured notes, issued amount		$ 100,000
Debt instrument, annual amortization (percent)		5.00%
Term Loan Facility | Swedish Kronor
Line of Credit Facility [Line Items]
Senior unsecured notes, issued amount		$ 150,000
Debt instrument, annual amortization (percent)		5.00%
Net proceeds from credit facility and long-term debt, including current portion		$ 150,000
Credit Agreement
Line of Credit Facility [Line Items]
Term of agreement		5 years
Long-term Debt, Gross		$ 233,721		$ 239,552
Credit Agreement | Swedish Kronor
Line of Credit Facility [Line Items]
Long-term Debt, Gross		150,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Net proceeds from credit facility and long-term debt, including current portion		100,000
Long-term Debt, Gross		191,000		$ 16,000
Standby Letters of Credit
Line of Credit Facility [Line Items]
Letters of Credit Outstanding, Amount		$ 238,200
Three Point One Two Five Percent Senior Unsecured Notes Due June Fifteenth Twenty Twenty Five [Domain]
Line of Credit Facility [Line Items]
Net proceeds from credit facility and long-term debt, including current portion	$ 421,000
Senior unsecured notes, interest rate		3.125%
BANK OF AMERICA, NATIONAL ASSOCIATION [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate at Period End		1.553%
Line of Credit Facility, Commitment Fee Percentage		0.20%