v3.21.2

Unsecured Credit Agreements - Summary of Unsecured Credit Agreements (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Sep. 15, 2021
Debt Instrument [Line Items]
Debt instrument, interest rate	5.00%
Total unsecured debt	$ 1,597,868	$ 1,547,667
Debt issuance costs, net	(4,658)	(6,435)
Long-term Debt	1,597,868
2031 Senior Unsecured Public Notes
Debt Instrument [Line Items]
Debt instrument, interest rate			2.60%
Total unsecured debt			$ 375,000
Unsecured Debt
Debt Instrument [Line Items]
Long-term Debt	1,490,123	1,433,796
Unsecured Debt | Term Loan [Member]
Debt Instrument [Line Items]
Total unsecured debt	650,000	965,000
Debt issuance costs, net	(3,542)	(3,670)
Long-term Debt	646,458	961,330
Unsecured Debt | Senior Notes [Member]
Debt Instrument [Line Items]
Total unsecured debt	850,000	475,000
Unamortized debt issuance costs and original issuance discount, net	6,335	2,534
Long-term Debt	$ 843,665	472,466
Unsecured Debt | Unsecured Revolving Credit Facility
Debt Instrument [Line Items]
Maturity Date	2023-09
Total unsecured debt	$ 0	0
Unsecured Debt | 2022 Unsecured Term Loan
Debt Instrument [Line Items]
Interest Rate	one-month LIBOR + 1.00%
Maturity Date	2022-02
Total unsecured debt	$ 60,000	$ 60,000
Unsecured Debt | 2022 Unsecured Term Loan | 1 Month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%	1.25%
Unsecured Debt | 2023 Unsecured Term Loan
Debt Instrument [Line Items]
Interest Rate	one-month LIBOR + 1.10%
Maturity Date	2023-01
Total unsecured debt	$ 0	$ 265,000
Unsecured Debt | 2023 Unsecured Term Loan | 1 Month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.10%	1.35%
Unsecured Debt | 2024 Unsecured Term Loan
Debt Instrument [Line Items]
Interest Rate	one-month LIBOR + 1.00%
Maturity Date	2024-06
Total unsecured debt	$ 190,000	$ 190,000
Unsecured Debt | 2024 Unsecured Term Loan | 1 Month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%	1.25%
Unsecured Debt | 2026 Unsecured Term Loan
Debt Instrument [Line Items]
Interest Rate	one-month LIBOR + 1.00%
Maturity Date	2026-02
Total unsecured debt	$ 400,000	$ 450,000
Unsecured Debt | 2026 Unsecured Term Loan | 1 Month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%	1.85%
Unsecured Debt | 2027 Senior Unsecured Notes | Senior Guaranteed Notes Series A
Debt Instrument [Line Items]
Debt instrument, interest rate	4.84%
Maturity Date	2027-04
Total unsecured debt	$ 150,000	$ 150,000
Unsecured Debt | 2028 Senior Unsecured Notes | Senior Guaranteed Notes Series B
Debt Instrument [Line Items]
Debt instrument, interest rate	5.09%
Maturity Date	2028-07
Total unsecured debt	$ 225,000	225,000
Unsecured Debt | 2030 Senior Unsecured Notes | Senior Guaranteed Notes Series C
Debt Instrument [Line Items]
Debt instrument, interest rate	5.19%
Maturity Date	2030-07
Total unsecured debt	$ 100,000	100,000
Unsecured Debt | 2031 Senior Unsecured Public Notes | Senior Notes
Debt Instrument [Line Items]
Debt instrument, interest rate	2.60%
Maturity Date	2031-09
Total unsecured debt	$ 375,000

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