Segment Information - Assets (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) segment	Dec. 31, 2017 USD ($)
Reconciliation of assets from segment to consolidated
Number of activity segments | segment	47
Net real estate	$ 13,001,513	$ 12,676,499
Goodwill	14,943	14,970
Other corporate assets	195,385	171,767
Total assets	14,474,093	14,058,166
Apparel
Reconciliation of assets from segment to consolidated
Net real estate	163,364	164,919
Intangible assets	35,631	36,600
Automotive service
Reconciliation of assets from segment to consolidated
Net real estate	211,628	213,156
Intangible assets	63,645	64,388
Goodwill	437	437
Automotive tire services
Reconciliation of assets from segment to consolidated
Net real estate	245,427	247,557
Intangible assets	9,945	10,383
Goodwill	862	862
Beverages
Reconciliation of assets from segment to consolidated
Net real estate	288,100	289,170
Intangible assets	1,958	2,022
Child care
Reconciliation of assets from segment to consolidated
Net real estate	60,769	61,527
Goodwill	4,909	4,924
Convenience stores
Reconciliation of assets from segment to consolidated
Net real estate	1,310,469	997,170
Intangible assets	115,761	45,445
Goodwill	2,004	2,004
Dollar stores
Reconciliation of assets from segment to consolidated
Net real estate	1,097,269	1,105,097
Intangible assets	47,071	47,905
Drug stores
Reconciliation of assets from segment to consolidated
Net real estate	1,528,130	1,518,443
Intangible assets	175,915	173,893
Financial services
Reconciliation of assets from segment to consolidated
Net real estate	381,092	384,867
Intangible assets	23,700	24,867
General merchandise
Reconciliation of assets from segment to consolidated
Net real estate	316,331	313,181
Intangible assets	47,912	50,184
Grocery stores
Reconciliation of assets from segment to consolidated
Net real estate	779,444	793,286
Intangible assets	147,048	140,780
Health and fitness
Reconciliation of assets from segment to consolidated
Net real estate	890,539	896,430
Intangible assets	76,690	76,276
Home improvement
Reconciliation of assets from segment to consolidated
Net real estate	424,429	407,002
Intangible assets	62,829	61,045
Motor vehicle dealerships
Reconciliation of assets from segment to consolidated
Net real estate	203,203	204,651
Intangible assets	30,828	31,720
Restaurants-casual dining
Reconciliation of assets from segment to consolidated
Net real estate	485,273	494,977
Intangible assets	19,590	20,079
Goodwill	2,058	2,062
Restaurants-quick service
Reconciliation of assets from segment to consolidated
Net real estate	720,717	681,763
Intangible assets	53,647	51,711
Goodwill	1,063	1,064
Theaters
Reconciliation of assets from segment to consolidated
Net real estate	565,080	566,585
Intangible assets	26,538	26,448
Transportation services
Reconciliation of assets from segment to consolidated
Net real estate	770,305	776,068
Intangible assets	83,631	87,162
Wholesale club
Reconciliation of assets from segment to consolidated
Net real estate	423,299	426,551
Intangible assets	28,818	29,596
Other non-reportable segments
Reconciliation of assets from segment to consolidated
Net real estate	2,136,645	2,134,099
Intangible assets	211,095	214,426
Goodwill	$ 3,610	$ 3,617