Segment Information - Assets (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($) segment	Dec. 31, 2016 USD ($)
Reconciliation of assets from segment to consolidated
Number of activity segments | segment	47
Net real estate	$ 12,347,776	$ 11,903,791
Goodwill	14,989	15,067
Other corporate assets	173,641	151,693
Total assets	13,701,419	13,152,871
Apparel
Reconciliation of assets from segment to consolidated
Net real estate	174,162	175,418
Intangible assets	40,553	43,786
Automotive service
Reconciliation of assets from segment to consolidated
Net real estate	215,004	152,220
Intangible assets	65,017	33,160
Goodwill	437	440
Automotive tire services
Reconciliation of assets from segment to consolidated
Net real estate	248,638	238,151
Intangible assets	10,281	11,533
Goodwill	862	862
Beverages
Reconciliation of assets from segment to consolidated
Net real estate	290,239	293,447
Intangible assets	2,087	2,280
Child care
Reconciliation of assets from segment to consolidated
Net real estate	58,148	49,584
Goodwill	4,924	4,945
Convenience stores
Reconciliation of assets from segment to consolidated
Net real estate	1,004,692	1,050,285
Intangible assets	46,399	14,372
Goodwill	2,004	2,008
Dollar stores
Reconciliation of assets from segment to consolidated
Net real estate	1,092,884	1,120,896
Intangible assets	47,061	51,249
Drug stores
Reconciliation of assets from segment to consolidated
Net real estate	1,510,098	1,541,846
Intangible assets	173,863	182,981
Financial services
Reconciliation of assets from segment to consolidated
Net real estate	393,395	408,228
Intangible assets	26,155	29,749
General merchandise
Reconciliation of assets from segment to consolidated
Net real estate	268,059	248,040
Intangible assets	44,425	43,248
Grocery stores
Reconciliation of assets from segment to consolidated
Net real estate	667,240	464,359
Intangible assets	121,654	65,412
Health and fitness
Reconciliation of assets from segment to consolidated
Net real estate	842,325	823,697
Intangible assets	67,138	63,574
Home improvement
Reconciliation of assets from segment to consolidated
Net real estate	360,866	311,459
Intangible assets	52,017	49,932
Motor vehicle dealerships
Reconciliation of assets from segment to consolidated
Net real estate	206,732	197,713
Intangible assets	32,618	25,032
Restaurants-casual dining
Reconciliation of assets from segment to consolidated
Net real estate	507,062	511,863
Intangible assets	20,574	22,058
Goodwill	2,080	2,107
Restaurants-quick service
Reconciliation of assets from segment to consolidated
Net real estate	639,812	574,532
Intangible assets	46,300	43,356
Goodwill	1,064	1,068
Theaters
Reconciliation of assets from segment to consolidated
Net real estate	538,781	370,732
Intangible assets	22,396	13,822
Transportation services
Reconciliation of assets from segment to consolidated
Net real estate	782,024	796,717
Intangible assets	90,750	101,664
Wholesale club
Reconciliation of assets from segment to consolidated
Net real estate	429,802	439,557
Intangible assets	30,378	32,723
Other non-reportable segments
Reconciliation of assets from segment to consolidated
Net real estate	2,117,813	2,135,047
Intangible assets	225,347	252,389
Goodwill	$ 3,618	$ 3,637