Condensed Consolidated Statements of Operations (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues:
Rental revenue	$ 140,797	$ 137,999	$ 281,028	$ 286,112
Observatory revenue	8,359	86	10,962	19,630
Lease termination fees	3,339	1,033	4,628	1,244
Third-party management and other fees	327	301	603	647
Other revenue and fees	586	1,611	1,491	3,621
Total revenues	153,408	141,030	298,712	311,254
Operating expenses:
Property operating expenses	28,793	29,750	59,072	71,218
Ground rent expenses	2,332	2,332	4,663	4,663
General and administrative expenses	14,089	18,149	27,942	34,100
Observatory expenses	5,268	4,002	9,856	12,156
Real estate taxes	31,354	29,579	62,801	58,833
Impairment charges	0	4,101	0	4,101
Depreciation and amortization	45,088	52,783	89,545	98,876
Total operating expenses	126,924	140,696	253,879	283,947
Total operating income (loss)	26,484	334	44,833	27,307
Other income (expense):
Interest income	164	1,526	286	2,163
Interest expense	(23,422)	(23,928)	(46,976)	(43,546)
Loss on early extinguishment of debt	0	0	(214)	(86)
Income (loss) before income taxes	3,226	(22,068)	(2,071)	(14,162)
Income tax benefit	1,185	2,450	3,291	2,832
Net income (loss)	4,411	(19,618)	1,220	(11,330)
Private perpetual preferred unit distributions	(1,051)	(1,047)	(2,101)	(2,097)
Net (income) loss attributable to non-controlling interests	(1,285)	7,872	335	5,129
Net income (loss) attributable to common stockholders	$ 2,075	$ (12,793)	$ (546)	$ (8,298)
Total weighted average shares:
Basic (in shares)	171,615	175,433	172,183	178,029
Diluted (in shares)	278,436	283,384	277,887	288,015
Earnings (loss) per share attributable to common stockholders:
Basic (in USD per share)	$ 0.01	$ (0.07)	$ (0.00)	$ (0.05)
Diluted (in USD per share)	0.01	(0.07)	(0.00)	(0.05)
Dividends per share (in USD per share)	$ 0.035	$ 0.105	$ 0.035	$ 0.210