Segment Information - Assets (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)
Reconciliation of assets from segment to consolidated
Number of activity segments | segment	50
Net real estate	$ 16,496,772	$ 13,843,517
Other corporate assets	564,641	217,369
Total assets	18,554,796	15,260,483
Automotive service
Reconciliation of assets from segment to consolidated
Net real estate	288,453	210,668
Intangible assets	58,854	61,951
Automotive tire services
Reconciliation of assets from segment to consolidated
Net real estate	232,709	238,939
Intangible assets	7,322	8,696
Beverages
Reconciliation of assets from segment to consolidated
Net real estate	279,373	284,910
Intangible assets	1,509	1,765
Child care
Reconciliation of assets from segment to consolidated
Net real estate	208,326	151,640
Intangible assets	21,997	12,277
Convenience Stores
Reconciliation of assets from segment to consolidated
Net real estate	2,057,157	1,756,732
Intangible assets	131,808	108,714
Dollar stores
Reconciliation of assets from segment to consolidated
Net real estate	1,427,950	1,117,250
Intangible assets	82,701	48,842
Drug stores
Reconciliation of assets from segment to consolidated
Net real estate	1,618,854	1,490,261
Intangible assets	183,319	165,558
Financial services
Reconciliation of assets from segment to consolidated
Net real estate	389,634	414,613
Intangible assets	17,130	20,426
General merchandise
Reconciliation of assets from segment to consolidated
Net real estate	475,418	317,424
Intangible assets	66,135	43,122
Grocery stores - U.S.
Reconciliation of assets from segment to consolidated
Net real estate	922,349	774,526
Intangible assets	180,197	144,551
Grocery stores - U.K.
Reconciliation of assets from segment to consolidated
Net real estate	663,210	0
Intangible assets	153,407	0
Health and fitness
Reconciliation of assets from segment to consolidated
Net real estate	1,019,796	882,515
Intangible assets	74,428	71,609
Home improvement
Reconciliation of assets from segment to consolidated
Net real estate	495,305	424,494
Intangible assets	72,979	57,928
Restaurants-casual dining
Reconciliation of assets from segment to consolidated
Net real estate	576,526	559,616
Intangible assets	23,289	18,153
Restaurants-quick service
Reconciliation of assets from segment to consolidated
Net real estate	1,059,155	964,980
Intangible assets	52,353	54,448
Theaters - U.S.
Reconciliation of assets from segment to consolidated
Net real estate	878,103	555,990
Intangible assets	36,089	25,811
Transportation services
Reconciliation of assets from segment to consolidated
Net real estate	769,614	758,133
Intangible assets	66,055	73,577
Wholesale club
Reconciliation of assets from segment to consolidated
Net real estate	396,690	412,203
Intangible assets	23,372	26,484
Other non-reportable segments
Reconciliation of assets from segment to consolidated
Net real estate	2,738,150	2,528,623
Intangible assets	$ 240,439	$ 255,685