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Dispositions of Property (Details) |  |  |  |  |  |  |  |  |  |  |  |  |  | 3 Months Ended | 9 Months Ended | 12 Months Ended
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Jan. 26, 2024 USD ($) | Dec. 06, 2023 USD ($) | Oct. 26, 2023 USD ($) | Aug. 09, 2023 USD ($) property | Mar. 10, 2023 USD ($) property | Dec. 28, 2022 USD ($) | Aug. 31, 2022 USD ($) property | Nov. 16, 2021 USD ($) property | Oct. 22, 2021 USD ($) | Sep. 23, 2021 USD ($) property | Aug. 31, 2021 USD ($) | Jun. 29, 2021 USD ($) | May 27, 2021 USD ($) property | Dec. 31, 2023 USD ($) | Sep. 30, 2023 USD ($) ft² | Sep. 30, 2023 USD ($) ft² | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($)
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets Held-for-sale, Not Part of Disposal Group |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 73,318,000 |  |  | $ 73,318,000 |  |
Real estate assets |  |  |  |  |  |  |  |  |  |  |  |  |  | 890,824,000 |  |  | 890,824,000 | $ 1,103,248,000 |
Straight-line rent receivable |  |  |  |  |  |  |  |  |  |  |  |  |  | 40,397,000 |  |  | 40,397,000 | 52,739,000 |
Deferred leasing commissions |  |  |  |  |  |  |  |  |  |  |  |  |  | 23,664,000 |  |  | 23,664,000 | 35,709,000 |
Operating results for discontinued operations: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rental revenue |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 27,157,000 | 43,025,000 | $ 84,179,000
Rental operating expenses |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (8,449,000) | (13,256,000) | (23,547,000)
Real estate taxes and insurance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (4,103,000) | (10,228,000) | (17,150,000)
Depreciation and amortization |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (7,206,000) | (14,656,000) | (27,025,000)
Income from dispositions and assets held for sale |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7,399,000 | $ 4,885,000 | $ 16,457,000
Office properties in Broomfield, Colorado |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of properties sold | property |  |  |  |  |  |  | 2 |  |  |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of property |  |  |  |  |  |  | $ 24,100,000 |  |  |  |  |  |  |  |  |  |  |  |
Sale price |  |  |  |  |  |  | $ 102,500,000 |  |  |  |  |  |  |  |  |  |  |  |
Property in Atlanta, Georgia |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of properties sold | property |  |  |  |  |  |  |  |  |  |  |  |  | 3 |  |  |  |  |  |
Assets Held-for-sale, Not Part of Disposal Group |  |  |  |  |  |  |  |  |  |  |  |  |  | 39,000,000.0 | $ 40,000,000.0 | $ 40,000,000.0 | 39,000,000.0 |  |
Gain (loss) on sale of property |  |  |  |  |  |  |  |  | $ 86,800,000 |  |  |  | $ 22,800,000 |  |  |  |  |  |
Sale price |  |  |  |  |  |  |  |  | $ 223,900,000 |  |  |  | $ 219,500,000 |  |  |  |  |  |
Real estate assets |  |  |  |  |  |  |  |  |  |  |  |  |  | 52,200,000 |  |  | 52,200,000 |  |
Straight-line rent receivable |  |  |  |  |  |  |  |  |  |  |  |  |  | 4,400,000 |  |  | 4,400,000 |  |
Deferred leasing commissions |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,900,000 |  |  | 2,900,000 |  |
Impairment charge |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 20,500,000 |  |  |
Office Property in Dulles, Virginia |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of property |  |  |  |  |  |  |  |  |  |  |  | $ (2,100,000) |  |  |  |  |  |  |
Sale price |  |  |  |  |  |  |  |  |  |  |  | $ 17,300,000 |  |  |  |  |  |  |
Office property in Indianapolis, Indiana |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of property |  |  |  |  |  |  |  |  |  |  | $ (1,700,000) |  |  |  |  |  |  |  |
Sale price |  |  |  |  |  |  |  |  |  |  | $ 35,000,000 |  |  |  |  |  |  |  |
Office Property in Evanston, Illinois |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of property |  |  |  |  |  | $ 3,900,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Sale price |  |  |  |  |  | $ 27,800,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Office properties in Chesterfield, MO |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of properties sold | property |  |  |  |  |  |  |  |  |  | 2 |  |  |  |  |  |  |  |  |
Gain (loss) on sale of property |  |  |  |  |  |  |  |  |  | $ 10,300,000 |  |  |  |  |  |  |  |  |
Sale price |  |  |  |  |  |  |  |  |  | $ 67,000,000 |  |  |  |  |  |  |  |  |
Office property in Chantilly, VA |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of properties sold | property |  |  |  |  |  |  |  | 2 |  |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of property |  |  |  |  |  |  |  | $ (2,900,000) |  |  |  |  |  |  |  |  |  |  |
Sale price |  |  |  |  |  |  |  | $ 40,000,000 |  |  |  |  |  |  |  |  |  |  |
Property in Plano, Texas |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets Held-for-sale, Not Part of Disposal Group |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 36,200,000 | $ 36,200,000 |  |  |
Gain (loss) on sale of property |  |  | $ 10,600,000 |  |  |  |  |  |  |  |  |  |  |  | 10,600,000 |  |  |  |
Sale price |  |  | $ 48,000,000.0 |  |  |  |  |  |  |  |  |  |  |  | 48,000,000.0 |  |  |  |
Office Property in Charlotte, North Carolina |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of properties sold | property |  |  |  | 1 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of property |  |  |  | $ (800,000) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sale price |  |  |  | $ 9,200,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Office Property in Elk Grove Village, Illinois |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of properties sold | property |  |  |  |  | 1 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of property |  |  |  |  | $ 8,400,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sale price |  |  |  |  | $ 29,100,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Property in Addison, Texas |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of property |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 53,000 |  |  |  |
Area of property (in square feet) | ft² |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7,826 | 7,826 |  |  |
Property in Miami, Florida |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of property |  | $ (18,900,000) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sale price |  | $ 68,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Properties in Miami, Florida and Atlanta, Georgia |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets Held-for-sale, Not Part of Disposal Group |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 96,400,000 | $ 96,400,000 |  |  |
Impairment charge |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 39,700,000 |  |  |  |
Properties In Richardson, Texas |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets Held-for-sale, Not Part of Disposal Group |  |  |  |  |  |  |  |  |  |  |  |  |  | 34,400,000 |  |  | 34,400,000 |  |
Sale price |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 35,000,000.0 |  |  |  |
Real estate assets |  |  |  |  |  |  |  |  |  |  |  |  |  | 31,100,000 |  |  | 31,100,000 |  |
Straight-line rent receivable |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,400,000 |  |  | 3,400,000 |  |
Deferred leasing commissions |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,000,000.0 |  |  | $ 2,000,000.0 |  |
Impairment charge |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 2,100,000 |  |  |  |  |
Properties In Richardson, Texas | Subsequent event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dispositions of Property |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gain (loss) on sale of property | $ (2,100,000) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sale price | $ 35,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

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- Definition Area of a real estate property. + References No definition available. + Details
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- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-28 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482130/360-10-45-4 + Details
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- Definition This element represents costs incurred by the lessor that are (a) costs to originate a lease incurred in transactions with independent third parties that (i) result directly from and are essential to acquire that lease and (ii) would not have been incurred had that leasing transaction not occurred and (b) certain costs directly related to specified activities performed by the lessor for that lease. Those activities are: evaluating the prospective lessee's financial condition; evaluating and recording guarantees, collateral, and other security arrangements; negotiating lease terms; preparing and processing lease documents; and closing the transaction. This element is net of accumulated amortization. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 840 -SubTopic 20 -Name Accounting Standards Codification -Section 25 -Paragraph 16 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481178/840-20-25-16 Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 840 -SubTopic 20 -Name Accounting Standards Codification -Section 35 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481123/840-20-35-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 842 -SubTopic 30 -Name Accounting Standards Codification -Section 25 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479341/842-30-25-10 Reference 4: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 840 -SubTopic 20 -Name Accounting Standards Codification -Section 25 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481178/840-20-25-17 + Details
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- Definition Amount of revenue attributable to disposal group, including, but not limited to, discontinued operation. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-7 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5B -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-5B + Details
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- Definition The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-28 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482130/360-10-45-5 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482099/360-10-50-3 + Details
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- Definition The cash inflow from the sale of formerly productive land held for sale, anything permanently fixed to it, including buildings, structures on it, and so forth. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 12 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-12 + Details
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- Definition Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)(d)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1 + Details
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