Real Estate Investments and Related Intangibles - Intangible Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Intangible lease assets:
Intangible lease assets, net	$ 925,511		$ 925,511		$ 928,844
Intangible lease liabilities:
Weighted-Average Useful Life			20 years 2 months 12 days
Intangible lease liabilities, net	111,140		$ 111,140		120,938
Accumulated amortization	113,251		113,251		106,504
Amortization expense	1,164	$ 393	$ 4,541	$ 1,929
In-place leases and other intangible assets [Member]
Intangible lease assets:
Weighted-Average Useful Life			17 years 4 months 24 days
Intangible lease assets, net	697,879		$ 697,879		745,026
Accumulated amortization	845,355		$ 845,355		810,597
Leasing commissions [Member]
Intangible lease assets:
Weighted-Average Useful Life			9 years 10 months 24 days
Intangible lease assets, net	17,347		$ 17,347		16,042
Accumulated amortization	9,352		$ 9,352		7,565
Above-market lease assets and deferred lease incentives [Member]
Intangible lease assets:
Weighted-Average Useful Life			23 years 2 months 12 days
Intangible lease assets, net	210,285		$ 210,285		167,776
Accumulated amortization	$ 137,033		137,033		$ 125,455
Above‑ And Below-Market Leases and Deferred Lease Incentives [Member]
Intangible lease liabilities:
Amortization expense			4,500	1,900
In-Place Leases, Leasing Commissions and Other Lease Intangibles [Member]
Intangible lease liabilities:
Amortization expense			$ 84,700	$ 103,500