Leases Narrative (Details) $ in Thousands			3 Months Ended	9 Months Ended		12 Months Ended	21 Months Ended
		Aug. 01, 2023 USD ($) ft²	Sep. 30, 2023 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2023 USD ($)
Lessee, Lease, Description [Line Items]
Operating Lease, Payments				$ (282)	$ (447)
Right of use assets - operating leases (amounts related to VIEs of $156,940 and $0 at September 30, 2023 and December 31, 2022, respectively)	[1]		$ 322,790	322,790		$ 167,351	$ 322,790
Lease liabilities - operating leases (amounts related to VIEs of $136,332 and $0 at September 30, 2023 and December 31, 2022, respectively)			341,299	341,299		204,686	341,299
343 Madison Avenue | Consolidated Entities
Lessee, Lease, Description [Line Items]
Consolidated Entities, Ownership Percentage		0.55
Lessee, Operating Lease, Term of Contract		99 years
Land Subject to Ground Leases | ft²		25,000
Lessee, Operating Lease, Option to Terminate		The joint venture has the option until July 31, 2025 to terminate the ground lease prior to construction of the new building and receive reimbursement of up to $117.0 million for the cost of the construction of Phase 1.
Operating Leases, Future Minimum Payments, Due in Two Years		$ 21,800
Operating Leases, Future Minimum Payments, Due in Five Years		$ 10,900
Lessee, Operating Lease Payment Increase (Decrease) Term, Year		5 years
Lessee, Operating Lease Payment Increase (Decrease), Percentage		1.10
Lessee, Operating Lease, Discount Rate		8.41%
Net Present Value and Operating Lease Liability		$ 134,500
Operating Lease, Payments				10,000		$ 15,000	$ 25,000
Right of use assets - operating leases (amounts related to VIEs of $156,940 and $0 at September 30, 2023 and December 31, 2022, respectively)		160,100
Lease liabilities - operating leases (amounts related to VIEs of $136,332 and $0 at September 30, 2023 and December 31, 2022, respectively)		134,509
Operating lease costs			$ 5,000	$ 5,000
343 Madison Avenue | Consolidated Entities | Scenario, Plan
Lessee, Lease, Description [Line Items]
Recovery of Direct Costs		$ 117,000
343 Madison Avenue | Consolidated Entities | Construction | Scenario, Plan
Lessee, Lease, Description [Line Items]
Net Rentable Area (in sf) | ft²		900,000

[1] See Note 4.