Segment Information - Assets (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($) segment	Dec. 31, 2018 USD ($)
Segment Reporting [Abstract]
Number of activity segments | segment	49
Reconciliation of assets from segment to consolidated
Net real estate	$ 15,146,726	$ 13,843,517
Intangible assets	1,313,798	1,199,597
Goodwill	14,503	14,630
Other corporate assets	704,877	202,739
Total assets	17,179,904	15,260,483
Automotive service
Reconciliation of assets from segment to consolidated
Net real estate	283,422	210,668
Intangible assets	58,974	61,951
Goodwill	436	437
Automotive tire services
Reconciliation of assets from segment to consolidated
Net real estate	232,712	238,939
Intangible assets	7,474	8,696
Goodwill	862	862
Beverages
Reconciliation of assets from segment to consolidated
Net real estate	280,427	284,910
Intangible assets	1,573	1,765
Child care
Reconciliation of assets from segment to consolidated
Net real estate	208,788	151,640
Intangible assets	20,448	12,277
Goodwill	4,825	4,863
Convenience stores
Reconciliation of assets from segment to consolidated
Net real estate	1,717,039	1,756,732
Intangible assets	104,901	108,714
Goodwill	1,978	1,983
Dollar stores
Reconciliation of assets from segment to consolidated
Net real estate	1,123,086	1,117,250
Intangible assets	48,294	48,842
Drug stores
Reconciliation of assets from segment to consolidated
Net real estate	1,447,853	1,490,261
Intangible assets	155,827	165,558
Financial services
Reconciliation of assets from segment to consolidated
Net real estate	394,771	414,613
Intangible assets	17,843	20,426
General merchandise
Reconciliation of assets from segment to consolidated
Net real estate	471,376	317,424
Intangible assets	60,080	43,122
Grocery stores - U.S.
Reconciliation of assets from segment to consolidated
Net real estate	865,039	774,526
Intangible assets	170,231	144,551
Grocery stores - U.K.
Reconciliation of assets from segment to consolidated
Net real estate	449,200	0
Intangible assets	108,863	0
Health and fitness
Reconciliation of assets from segment to consolidated
Net real estate	995,315	882,515
Intangible assets	68,738	71,609
Home improvement
Reconciliation of assets from segment to consolidated
Net real estate	487,219	424,494
Intangible assets	72,128	57,928
Restaurants-casual dining
Reconciliation of assets from segment to consolidated
Net real estate	529,316	559,616
Intangible assets	16,944	18,153
Goodwill	1,794	1,841
Restaurants-quick service
Reconciliation of assets from segment to consolidated
Net real estate	1,008,276	964,980
Intangible assets	52,662	54,448
Goodwill	1,040	1,052
Theaters
Reconciliation of assets from segment to consolidated
Net real estate	889,931	555,990
Intangible assets	35,989	25,811
Transportation services
Reconciliation of assets from segment to consolidated
Net real estate	735,020	758,133
Intangible assets	64,758	73,577
Wholesale club
Reconciliation of assets from segment to consolidated
Net real estate	402,478	412,203
Intangible assets	24,150	26,484
Other non-reportable segments
Reconciliation of assets from segment to consolidated
Net real estate	2,625,458	2,528,623
Intangible assets	223,921	255,685
Goodwill	$ 3,568	$ 3,592