Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Amount of unamortized debt discount (premium) and debt issuance costs.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest.

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The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

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The cash inflow from the issuance of long-term debt that is not secured by collateral. Excludes proceeds from tax exempt unsecured debt.

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Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

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Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

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Long-Term Debt (Details) - USD ($) $ in Thousands		12 Months Ended
Long-Term Debt (Details) - USD ($) $ in Thousands	Aug. 03, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Mar. 29, 2019
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 745,882	$ 680,552
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net		7,490	3,689
Long-term Debt		738,392	676,863
Long-term debt, current portion		13,473	12,444
Long-term Debt, Excluding Current Maturities		724,919	648,419
Gain (Loss) on Extinguishment of Debt		9,126	0	$ 0
Senior unsecured notes, proceeds		494,234	0	0
Payment for Debt Extinguishment or Debt Prepayment Cost		(8,509)	0	$ 0
Write off of Deferred Debt Issuance Cost		600
Letter of Credit		$ 14,100
BANK OF AMERICA, NATIONAL ASSOCIATION [Member]
Debt Instrument [Line Items]
Commitment fee rate		0.175%
Minimum
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.00%
Commitment fee rate		0.125%
Maximum
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.375%
Commitment fee rate		0.20%
Sweden, Kronor
Debt Instrument [Line Items]
Proceeds from Debt, Net of Issuance Costs		$ 150,000
Credit Agreement \| United States of America, Dollars
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 91,250	$ 96,250
Senior unsecured notes, interest rate		1.504%	1.945%
Debt Instrument, Interest Rate, Effective Percentage		1.769%	2.196%
Senior unsecured notes, maturity date		Mar. 29, 2024
Credit Agreement \| Sweden, Kronor
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 154,632	$ 143,302		$ 150,000
Senior unsecured notes, interest rate		1.25%	1.348%
Debt Instrument, Interest Rate, Effective Percentage		1.484%	1.601%
Senior unsecured notes, maturity date		Mar. 29, 2024
Term loan facility [Member] \| United States of America, Dollars
Debt Instrument [Line Items]
Proceeds from Debt, Net of Issuance Costs		$ 100,000
Revolving Credit Facility
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 0	$ 16,000
Senior unsecured notes, interest rate		1.397%	1.799%
Debt Instrument, Interest Rate, Effective Percentage		1.397%	1.799%
Senior unsecured notes, maturity date		Mar. 29, 2024
Repayments of Lines of Credit		$ 191,000
Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Letter of Credit		270,500
Unsecured notes
Debt Instrument [Line Items]
Long-term Debt, Gross		175,000
Unsecured notes \| Senior 2030 Notes [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 500,000	$ 0
Senior unsecured notes, interest rate		2.50%	0.00%
Debt Instrument, Interest Rate, Effective Percentage		2.63%	0.00%
Senior unsecured notes, maturity date		Aug. 01, 2030
Proceeds from Debt, Net of Issuance Costs	$ 494,200
Unsecured notes \| Senior 2021 Notes [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 0	$ 425,000
Senior unsecured notes, interest rate		0.00%	3.125%
Debt Instrument, Interest Rate, Effective Percentage		0.00%	3.343%
Senior unsecured notes, maturity date		Jun. 15, 2021
Revolving Credit Facility
Debt Instrument [Line Items]
Proceeds from Debt, Net of Issuance Costs		$ 100,000
Line of Credit Facility, Remaining Borrowing Capacity		$ 200,000