Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Rental revenue													$ 563,071	$ 586,414
Rental revenue															$ 493,231
Tenant expense reimbursement													0	0	72,372
Observatory revenue													29,057	128,769	131,227
Lease termination fees													9,416	4,352	20,847
Third-party management and other fees													1,225	1,254	1,440
Other revenue and fees													6,459	10,554	12,394
Total revenues	$ 151,399	$ 146,575	$ 141,030	$ 170,224	$ 194,933	$ 192,873	$ 176,244	$ 167,293	$ 199,309	$ 186,402	$ 178,529	$ 167,271	609,228	731,343	731,511
Operating expenses:
Property operating expenses													136,141	174,977	167,379
Ground rent expenses													9,326	9,326	9,326
General and administrative expenses													62,244	61,063	52,674
Observatory expenses													23,723	33,767	32,767
Real estate taxes													121,923	115,916	110,000
Impairment charges													6,204	0	0
Depreciation and amortization													191,006	181,588	168,508
Total operating expenses													550,567	576,637	540,654
Total operating income	19,426	11,928	334	26,973	47,112	45,279	36,239	26,076	58,490	48,538	49,665	34,164	58,661	154,706	190,857
Other income (expense):
Interest income													2,637	11,259	10,661
Interest expense													(89,907)	(79,246)	(79,623)
Loss on early extinguishment of debt													(86)	0	0
IPO litigation expense													(1,165)	0	0
Income (loss) before income taxes													(29,860)	86,719	121,895
Income tax benefit (expense)													6,971	(2,429)	(4,642)
Net income (loss)	$ 710	$ (12,269)	$ (19,618)	$ 8,288	$ 28,720	$ 26,784	$ 18,930	$ 9,856	$ 39,781	$ 29,230	$ 30,184	$ 18,058	(22,889)	84,290	117,253
Private perpetual preferred unit distributions													(4,197)	(1,743)	(936)
Net (income) loss attributable to non-controlling interest													10,374	(33,102)	(50,714)
Net income (loss) attributable to common stockholders													$ (16,712)	$ 49,445	$ 65,603
Total weighted average shares:
Basic (in shares)													175,169	178,340	167,571
Diluted (in shares)													283,837	297,798	297,259
Earnings (loss) per share attributable to common stockholders:
Basic (in USD per share)													$ (0.10)	$ 0.28	$ 0.39
Diluted (in USD per share)													$ (0.10)	$ 0.28	$ 0.39