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

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

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.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=123466204&loc=SL6031897-161870

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69C
-URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69B
-URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Notes and Bonds Payable (Details) - USD ($)	12 Months Ended
Notes and Bonds Payable (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Oct. 02, 2020	Mar. 18, 2020	Dec. 11, 2017	Apr. 24, 2015
Debt Instrument [Line Items]
Notes and bonds payable	$ 1,801,325,000	$ 1,602,769,000
Line of Credit \| Unsecured Credit Facility
Debt Instrument [Line Items]
Notes and bonds payable	210,000,000	0
Medium-term Notes \| Term Loan due 2024
Debt Instrument [Line Items]
Notes and bonds payable	$ 199,460,000	199,236,000
Contractual interest rates, basis spread on variable rate	1.00%
Medium-term Notes \| Term Loan due 2026
Debt Instrument [Line Items]
Notes and bonds payable	$ 149,376,000	149,479,000
Senior Notes \| Senior Notes due 2025
Debt Instrument [Line Items]
Notes and bonds payable	$ 249,040,000	248,776,000
Contractual interest rates	3.88%					3.875%
Senior Notes \| Senior Notes due 2028
Debt Instrument [Line Items]
Notes and bonds payable	$ 296,612,000	296,123,000
Contractual interest rates	3.63%				3.625%
Senior Notes \| Senior Notes due 2030
Debt Instrument [Line Items]
Notes and bonds payable	$ 296,813,000	296,468,000
Contractual interest rates	2.40%			2.40%
Senior Notes \| Senior Notes due 2031
Debt Instrument [Line Items]
Notes and bonds payable	$ 295,374,000	294,924,000
Contractual interest rates	2.05%		2.05%
Mortgage Notes \| Mortgage Notes Payable
Debt Instrument [Line Items]
Notes and bonds payable	$ 104,650,000	$ 117,763,000
LIBOR \| Line of Credit \| Unsecured Credit Facility
Debt Instrument [Line Items]
Contractual interest rates, basis spread on variable rate	0.90%
LIBOR \| Medium-term Notes \| Term Loan due 2024
Debt Instrument [Line Items]
Contractual interest rates, basis spread on variable rate	1.00%
LIBOR \| Medium-term Notes \| Term Loan due 2026
Debt Instrument [Line Items]
Contractual interest rates, basis spread on variable rate	0.95%
Minimum \| Medium-term Notes \| Term Loan due 2024
Debt Instrument [Line Items]
Contractual interest rates, basis spread on variable rate	0.85%
Minimum \| Medium-term Notes \| Term Loan due 2026
Debt Instrument [Line Items]
Contractual interest rates, basis spread on variable rate	1.45%
Minimum \| Mortgage Notes
Debt Instrument [Line Items]
Contractual interest rates	3.30%
Minimum \| Mortgage Notes \| Mortgage Notes Payable
Debt Instrument [Line Items]
Contractual interest rates	3.31%
Maximum \| Medium-term Notes \| Term Loan due 2024
Debt Instrument [Line Items]
Contractual interest rates, basis spread on variable rate	1.65%
Maximum \| Medium-term Notes \| Term Loan due 2026
Debt Instrument [Line Items]
Contractual interest rates, basis spread on variable rate	2.40%
Maximum \| Mortgage Notes
Debt Instrument [Line Items]
Contractual interest rates	6.20%
Maximum \| Mortgage Notes \| Mortgage Notes Payable
Debt Instrument [Line Items]
Contractual interest rates	6.17%