Condensed Consolidated Statements of Income (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Rental revenue	$ 150,225		$ 434,713
Rental revenue		$ 123,621		$ 369,970
Tenant expense reimbursement	0	18,627	0	52,626
Observatory revenue	37,575	40,241	91,039	96,691
Lease termination fees	2,361	1,185	3,112	2,164
Third-party management and other fees	304	312	955	1,151
Other revenue and fees	2,408	2,416	6,591	9,600
Total revenues	192,873	186,402	536,410	532,202
Operating expenses:
Property operating expenses	47,894	42,772	131,076	126,375
Ground rent expenses	2,331	2,331	6,994	6,994
General and administrative expenses	14,421	13,148	44,445	39,001
Observatory expenses	9,089	8,854	25,024	23,868
Real estate taxes	29,599	28,284	86,098	81,771
Depreciation and amortization	44,260	42,475	135,179	121,826
Total operating expenses	147,594	137,864	428,816	399,835
Total operating income	45,279	48,538	107,594	132,367
Other income (expense):
Interest income	2,269	3,485	9,907	7,209
Interest expense	(19,426)	(20,658)	(60,712)	(58,774)
Income before income taxes	28,122	31,365	56,789	80,802
Income tax expense	(1,338)	(2,135)	(1,219)	(3,330)
Net income	26,784	29,230	55,570	77,472
Private perpetual preferred unit distributions	(234)	(234)	(702)	(702)
Net income attributable to non-controlling interests	(10,668)	(12,654)	(22,222)	(34,009)
Net income attributable to common stockholders	$ 15,882	$ 16,342	$ 32,646	$ 42,761
Total weighted average shares:
Basic (in shares)	178,352	167,657	177,428	165,613
Diluted (in shares)	298,151	297,478	298,117	297,181
Earnings per share attributable to common stockholders:
Basic (in USD per share)	$ 0.09	$ 0.10	$ 0.18	$ 0.26
Diluted (in USD per share)	0.09	0.10	0.18	0.26
Dividends per share (in USD per share)	$ 0.105	$ 0.105	$ 0.315	$ 0.315