Investments in Real Estate - Acquisitions Allocation (Details) € in Thousands, £ in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2022 GBP (£)	Sep. 30, 2022 EUR (€)	Sep. 30, 2021 USD ($)	Sep. 30, 2021 GBP (£)	Sep. 30, 2021 EUR (€)	Sep. 30, 2022 GBP (£)	Dec. 31, 2021 USD ($)
Acquisitions
Weighted average amortization period for acquired lease intangible assets	10 years 10 months 24 days	10 years 10 months 24 days	10 years 10 months 24 days	13 years 1 month 6 days	13 years 1 month 6 days	13 years 1 month 6 days
Right of use asset - operating leases, net	$ 592,800							$ 631,515
Weighted average amortization period for acquired lease intangible liabilities	13 years 9 months 18 days	13 years 9 months 18 days	13 years 9 months 18 days	18 years 7 months 6 days	18 years 7 months 6 days	18 years 7 months 6 days
Real Estate Investment | U.S.
Acquisitions
Land	$ 729,400			$ 596,800
Buildings and improvements	1,572,100			991,000
Lease intangible assets	305,500			349,800
Other assets	386,600			372,600
Lease intangible liabilities	(72,300)			(46,700)
Other liabilities	(21,800)			(122,300)
Net	2,899,500			2,141,200
Allocated to other assets, financing receivables with above-market terms	353,800			68,200
Allocated to other assets, finance lease right-of-use assets	32,800			39,100
Allocated to other assets, investments in sales-type leases				5,800
Allocated to other assets, right-of-use assets under ground leases accounted for as operating leases				259,500
Deferred rent on below market leases	15,300			21,600
Lease liabilities under finance leases	8,600
Mortgage discounts	$ 2,100
Allocated to other liabilities, lease liabilities under ground leases accounted for as operating leases				$ 100,700
Real Estate Investment | U.K.
Acquisitions
Land | £		£ 595,700			£ 292,300
Buildings and improvements | £		556,800			529,600
Lease intangible assets | £		210,000			179,700
Other assets | £		203,200			25,900
Lease intangible liabilities | £		(54,300)			(6,400)
Other liabilities | £		(2,400)			(300)
Net | £		1,509,000			1,020,800
Allocated to land, right of use assets under long-term ground leases | £		43,500			1,300
Allocated to other assets, financing receivables with above-market terms | £		15,900			4,300
Allocated to other assets, finance lease right-of-use assets | £		£ 184,900			£ 21,700
Right of use asset - operating leases, net | £							£ 2,400
Real Estate Investment | Spain
Acquisitions
Land | €			€ 63,200			€ 36,700
Buildings and improvements | €			80,500			36,300
Lease intangible assets | €			12,400			23,200
Other assets | €			8,700			0
Lease intangible liabilities | €			(1,100)			0
Other liabilities | €			0			0
Net | €			€ 163,700			€ 96,200