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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Foreign exchange rate used to translate amounts denominated in functional currency to reporting currency.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

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Revolving Credit Facility and Term Loan, Net - Outstanding Balance Under Credit Agreement (Details) € in Thousands, £ in Thousands, $ in Thousands	Sep. 30, 2021 USD ($)	Sep. 30, 2021 $ / €	Sep. 30, 2021 GBP (£)	Sep. 30, 2021 EUR (€)	Sep. 30, 2021 $ / £	Dec. 31, 2020 USD ($)	Dec. 31, 2020 $ / €	Dec. 31, 2020 GBP (£)	Dec. 31, 2020 EUR (€)	Dec. 31, 2020 $ / £
Line of Credit Facility [Line Items]
Revolving Credit Facility	$ 118,676					$ 111,132
Term Loan, Net	284,342					300,154
Foreign currency exchange rate (GBP, EUR, CAD per USD)		1.16			1.35		1.23			1.37
KeyBank National Association \| Credit Facility \| Unsecured debt
Line of Credit Facility [Line Items]
Total Credit Facility	403,018					411,286
KeyBank National Association \| Credit Facility \| Unsecured debt \| USD
Line of Credit Facility [Line Items]
Total Credit Facility	90,000					105,000
KeyBank National Association \| Credit Facility \| Unsecured debt \| GBP
Line of Credit Facility [Line Items]
Total Credit Facility \| £			£ 17,000					£ 0
KeyBank National Association \| Credit Facility \| Unsecured debt \| EUR
Line of Credit Facility [Line Items]
Total Credit Facility \| €				€ 252,075					€ 252,075
KeyBank National Association \| Credit Facility \| Unsecured debt \| Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving Credit Facility	118,676					111,132
KeyBank National Association \| Credit Facility \| Unsecured debt \| Revolving Credit Facility \| USD
Line of Credit Facility [Line Items]
Revolving Credit Facility	90,000					105,000
KeyBank National Association \| Credit Facility \| Unsecured debt \| Revolving Credit Facility \| GBP
Line of Credit Facility [Line Items]
Revolving Credit Facility \| £			17,000					0
KeyBank National Association \| Credit Facility \| Unsecured debt \| Revolving Credit Facility \| EUR
Line of Credit Facility [Line Items]
Revolving Credit Facility \| €				5,000					5,000
KeyBank National Association \| Credit Facility \| Unsecured debt \| Term Facility
Line of Credit Facility [Line Items]
Term Loan	286,349					303,036
Deferred financing costs	(2,007)					(2,882)
Term Loan, Net	284,342					300,154
KeyBank National Association \| Credit Facility \| Unsecured debt \| Term Facility \| USD
Line of Credit Facility [Line Items]
Term Loan	0					0
Deferred financing costs	0					0
Term Loan, Net	$ 0					$ 0
KeyBank National Association \| Credit Facility \| Unsecured debt \| Term Facility \| GBP
Line of Credit Facility [Line Items]
Term Loan \| £			0					0
Deferred financing costs \| £			0					0
Term Loan, Net \| £			£ 0					£ 0
KeyBank National Association \| Credit Facility \| Unsecured debt \| Term Facility \| EUR
Line of Credit Facility [Line Items]
Term Loan \| €				247,075					247,075
Deferred financing costs \| €				0					0
Term Loan, Net \| €				€ 247,075					€ 247,075