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

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Maximum amount of additional loans that may be issued under the accordion feature of the debt agreement subject to receipt of lender commitments and satisfaction of certain customary conditions.

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Representing fixed charge coverage ratio.

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The length of time the company can extend the maturity date on the debt instrument.

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The increase in the maximum borrowing capacity under the credit facility upon exercise of the accordion feature which is subject to receipt of lender commitments and satisfaction of certain customary conditions.

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The number of periods the company can extend the maturity date of the debt instrument.

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Represents the unsecured leverage ratio that must be maintained as a part of the debt agreement.

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Face (par) amount of debt instrument at time of issuance.

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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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Weighted average interest rate of debt outstanding.

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Fixed interest rate related to the interest rate derivative.

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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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Amount of liability hedged in fair value hedging relationship.

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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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The effective interest rate at the end of the reporting period.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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The cash outflow for a financial contract that meets the hedge criteria as either cash flow hedge, fair value hedge or hedge of net investment in foreign operations.

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The cash outflow to repay long-term debt that is not secured by collateral. Excludes repayments of tax exempt unsecured debt.

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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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Bank Note Payable, Term Loans Payable and Senior Notes (Details)			3 Months Ended	9 Months Ended
	Jun. 04, 2021 USD ($)	Dec. 24, 2020 USD ($)	Sep. 30, 2021 USD ($) period	Sep. 30, 2021 USD ($) period	Dec. 31, 2020 USD ($)	Dec. 23, 2020 USD ($)	Aug. 02, 2018 USD ($)
Debt Instrument [Line Items]
Repayments of unsecured debt				$ 245,000,000
Loss on extinguishment of debt			$ (236,000)	(403,000)
Unsecured term loan			473,648,000	473,648,000	$ 717,323,000
Portion of future LIBOR-based rate risk			7,600,000	7,600,000
Borrowings outstanding					$ 3,500,000
Senior Notes
Debt Instrument [Line Items]
Principal amount of loan			200,000,000	$ 200,000,000
Fixed charge coverage ratio				1.50
Series A Notes
Debt Instrument [Line Items]
Principal amount of loan			$ 116,000,000	$ 116,000,000
Interest rate (as a percent)			4.49%	4.49%
Series B Notes
Debt Instrument [Line Items]
Principal amount of loan			$ 84,000,000	$ 84,000,000
Interest rate (as a percent)			4.76%	4.76%
Maximum \| Senior Notes
Debt Instrument [Line Items]
Unsecured leverage ratio				60.00%
Unsecured leverage ratio for significant acquisition				65.00%
BAML Revolver
Debt Instrument [Line Items]
Weighted average interest rate (as a percent)			1.32%	1.32%	1.65%
Effective interest rate (as a percent)			1.63%	1.63%
Total available			$ 600,000,000	$ 600,000,000
Number of periods of extension \| period			2	2
Length of extension period				6 months
Additional borrowing capacity allowed by exercising an accordion feature			$ 500,000,000	$ 500,000,000
Borrowings outstanding			$ 0	$ 0	$ 3,500,000
Facility fee at period end (as a percent)			0.30%	0.30%
BAML Revolver \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate at period end (as a percent)			1.55%	1.55%
BAML Revolver \| Bank's base rate
Debt Instrument [Line Items]
Basis spread on variable rate at period end (as a percent)			0.55%	0.55%
BAML Term Loan
Debt Instrument [Line Items]
Principal amount of loan			$ 400,000,000	$ 400,000,000
Repayments of unsecured debt				90,000,000
Loss on extinguishment of debt				(200,000)
Unsecured term loan			$ 310,000,000	$ 310,000,000
Weighted average interest rate (as a percent)			1.84%	1.84%
Effective interest rate (as a percent)			1.83%	1.83%
Additional borrowing capacity allowed by exercising an accordion feature			$ 500,000,000	$ 500,000,000
BAML Term Loan \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate at period end (as a percent)			1.75%	1.75%
Fixed rate (as a percent)			1.12%	1.12%
BAML Term Loan \| Bank's base rate
Debt Instrument [Line Items]
Basis spread on variable rate at period end (as a percent)			0.75%	0.75%
JPM Term Loan
Debt Instrument [Line Items]
Principal amount of loan							$ 150,000,000
Repayments of unsecured debt	$ 100,000,000	$ 50,000,000
Loss on extinguishment of debt	100,000
Unsecured term loan						$ 100,000,000
Portion of future LIBOR-based rate risk			$ 100,000,000	$ 100,000,000
JPM Term Loan \| Hedged portion
Debt Instrument [Line Items]
Payment to terminate interest rate swap	1,200,000
Portion of future LIBOR-based rate risk			$ 100,000,000	$ 100,000,000
JPM Term Loan \| LIBOR \| Hedged portion
Debt Instrument [Line Items]
Fixed rate (as a percent)			2.44%	2.44%
BMO Term Loan
Debt Instrument [Line Items]
Principal amount of loan			$ 220,000,000	$ 220,000,000
Additional loans allowed by exercising an accordion feature			$ 100,000,000	$ 100,000,000
Effective interest rate (as a percent)			4.04%	4.04%
BMO Term Loan \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate at period end (as a percent)			1.65%	1.65%
Fixed rate (as a percent)			2.32%	2.32%
BMO Term Loan \| LIBOR \| Hedged portion
Debt Instrument [Line Items]
Fixed rate (as a percent)			2.39%	2.39%
BMO Term Loan \| Bank's base rate
Debt Instrument [Line Items]
Basis spread on variable rate at period end (as a percent)			0.65%	0.65%
Tranche A Term Loan
Debt Instrument [Line Items]
Principal amount of loan			$ 55,000,000	$ 55,000,000
Loss on extinguishment of debt	100,000
Payment to terminate interest rate swap	$ 600,000
Tranche B Term Loan
Debt Instrument [Line Items]
Principal amount of loan			$ 165,000,000	$ 165,000,000