Basis of Presentation and Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) development_site variableInterestEntity property property_partnership segment investment	Dec. 31, 2022 USD ($) property investment variableInterestEntity	Dec. 31, 2021 USD ($)
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Assets	$ 11,401,045,000	$ 10,796,987,000
Liabilities	5,741,352,000	5,122,026,000
Noncontrolling interest in consolidated subsidiary	$ 178,257,000	$ 184,390,000
Number of equity method investments | investment	0	0
Number of properties classified as held for sale | property	0	0
Number of consolidated property partnerships | property_partnership	3
Conversion ratio	1
Income tax provision	$ 0	$ 0	$ 0
Number of operating segments | segment	1
Lease Agreements | Minimum
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Finite-lived intangible asset, useful life	1 year
Lease Agreements | Maximum
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Finite-lived intangible asset, useful life	20 years
Disposal group, disposed of by sale
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Restricted cash	$ 0	0
Building and building improvements
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Depreciation of real estate	$ 300,100,000	$ 287,800,000	$ 256,300,000
Building and building improvements | Minimum
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Property depreciable lives	25 years
Building and building improvements | Maximum
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Property depreciable lives	40 years
Leasehold improvements | Minimum
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Property depreciable lives	1 year
Leasehold improvements | Maximum
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Property depreciable lives	20 years
Stabilized Office Properties | Washington
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of buildings | property	10
Stabilized Office Properties | Texas
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of buildings | property	1
Future development project | Washington
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of buildings | development_site	1
Future development project | Texas
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of buildings | development_site	1
Variable Interest Entity, Primary Beneficiary
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of VIEs | variableInterestEntity	2	2
Assets	$ 416,700,000	$ 438,700,000
Liabilities	23,600,000	31,500,000
Variable Interest Entity, Primary Beneficiary | 100 First LLC and 303 Second LLC
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling interest in consolidated subsidiary	173,700,000	179,400,000
Variable Interest Entity, Primary Beneficiary | Real estate investment
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Assets	$ 350,000,000	$ 362,700,000