Fair Value Measurements (Schedule of Derivative Instruments) (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024	Jan. 31, 2024
Derivative [Line Items]
Long term debt	$ 2,117,577	$ 2,566,862
Matures in May 2028 | 555 California Street | Office
Derivative [Line Items]
Equity method ownership percentage	70.00%	70.00%
Debt amount	$ 1,200,000	$ 1,200,000
Designated as Hedging Instrument
Derivative [Line Items]
Fair Value Asset	56,037	88,982
Fair Value Liability	$ 2,103	1,023
Designated as Hedging Instrument | Interest rate swaps
Derivative [Line Items]
Notional amount and swapped balance			$ 100,000
Unswapped Balance interest rate	1.30%
Designated as Hedging Instrument | 555 California Street mortgage loan | Interest rate swaps
Derivative [Line Items]
Notional amount and swapped balance	$ 840,000
All-In Swapped Rate	6.03%
Fair Value Asset	$ 0	765
Fair Value Liability	1,149	0
Designated as Hedging Instrument | 770 Broadway mortgage loan | Interest rate swaps
Derivative [Line Items]
Notional amount and swapped balance	$ 700,000
All-In Swapped Rate	4.98%
Fair Value Asset	$ 13,911	21,332
Fair Value Liability	0	0
Designated as Hedging Instrument | PENN 11 mortgage loan | Interest rate swaps
Derivative [Line Items]
Notional amount and swapped balance	$ 500,000
All-In Swapped Rate	6.28%
Fair Value Asset	$ 0	17
Fair Value Liability	231	282
Designated as Hedging Instrument | Unsecured revolving credit facility | Interest rate swaps
Derivative [Line Items]
Notional amount and swapped balance	$ 575,000
All-In Swapped Rate	3.88%
Fair Value Asset	$ 12,056	18,510
Fair Value Liability	0	0
Designated as Hedging Instrument | Unsecured term loan | Interest rate swaps
Derivative [Line Items]
Notional amount and swapped balance	$ 700,000
All-In Swapped Rate	4.53%
Fair Value Asset	$ 6,218	10,128
Fair Value Liability	0	0
Designated as Hedging Instrument | 100 West 33rd Street mortgage loan | Interest rate swaps
Derivative [Line Items]
Notional amount and swapped balance	$ 480,000
All-In Swapped Rate	5.26%
Fair Value Asset	$ 2,535	6,808
Fair Value Liability	0	0
Designated as Hedging Instrument | 888 Seventh Avenue mortgage loan | Interest rate swaps
Derivative [Line Items]
Notional amount and swapped balance	$ 200,000
All-In Swapped Rate	4.76%
Fair Value Asset	$ 3,104	5,249
Fair Value Liability	0	0
Long term debt	$ 53,688
Derivative, basis spread on variable rate	1.80%
Variable interest rate	6.12%
Designated as Hedging Instrument | 435 Seventh Avenue mortgage loan | Interest rate swaps
Derivative [Line Items]
Notional amount and swapped balance	$ 75,000
All-In Swapped Rate	6.96%
Fair Value Asset	$ 0	0
Fair Value Liability	723	741
Designated as Hedging Instrument | 4 Union Square South mortgage loan | Interest rate swaps
Derivative [Line Items]
Fair Value Asset	0	12
Fair Value Liability	0	0
Designated as Hedging Instrument | 1290 Avenue of the Americas mortgage loan | Interest Rate Cap
Derivative [Line Items]
Notional amount and swapped balance	950,000
Fair Value Asset	18,197	25,673
Fair Value Liability	$ 0	0
Cap strike rate	1.00%
Designated as Hedging Instrument | Various mortgage loans | Interest Rate Cap
Derivative [Line Items]
Fair Value Asset	$ 16	488
Fair Value Liability	0	$ 0
Designated as Hedging Instrument | Unsecured Term Loan Expiring July 2025 | Interest rate swaps
Derivative [Line Items]
Notional amount and swapped balance	$ 700,000
All-In Swapped Rate	4.53%
Unswapped Balance	$ 100,000
Designated as Hedging Instrument | Unsecured Term Loan Expiring October 2026 | Interest rate swaps
Derivative [Line Items]
Notional amount and swapped balance	$ 550,000
All-In Swapped Rate	4.36%
Unswapped Balance	$ 250,000
Designated as Hedging Instrument | Unsecured Term Loan Expiring August 2027 | Interest rate swaps
Derivative [Line Items]
Notional amount and swapped balance	$ 50,000
All-In Swapped Rate	4.04%
Unswapped Balance	$ 750,000