Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 17,882	$ 4,572
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization, including amortization of debt issuance costs	8,958	9,202
Straight-lining of rental income	2,637	1,935
Change in fair value of marketable securities	(582)	11,395
Changes in operating assets and liabilities:
Tenant and other receivables	1,286	1,225
Other assets	14,278	(12,707)
Amounts due to Vornado	430	(597)
Accounts payable and accrued expenses	9,240	10,166
Other liabilities	(163)	(156)
Net cash provided by operating activities	53,966	25,035
CASH FLOWS FROM INVESTING ACTIVITIES
Construction in progress and real estate additions	(3,842)	(6,961)
Return of short-term investment	3,600	0
Net cash used in investing activities	(242)	(6,961)
CASH FLOWS FROM FINANCING ACTIVITIES
Dividends paid	(23,050)	(23,034)
Debt issuance costs	(35)	(79)
Proceeds from borrowing	0	145,708
Net cash (used in) provided by financing activities	(23,085)	122,595
Net increase in cash and cash equivalents and restricted cash	30,639	140,669
Cash and cash equivalents and restricted cash at beginning of period	449,877	313,977
Cash and cash equivalents and restricted cash at end of period	480,516	454,646
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH
Cash and cash equivalents at beginning of period	428,710	298,063
Restricted cash at beginning of period	21,167	15,914
Cash and cash equivalents and restricted cash at beginning of period	449,877	313,977
Cash and cash equivalents at end of period	459,384	438,342
Restricted cash at end of period	21,132	16,304
Cash and cash equivalents and restricted cash at end of period	480,516	454,646
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash payments for interest	4,565	7,805
NON-CASH TRANSACTIONS
Liability for real estate additions, including $33 and $146 for development fees due to Vornado in 2021 and 2020, respectively	2,913	3,209
Write-off of fully depreciated assets	$ 5,628	$ 367