Summary of Significant Accounting Policies and Procedures and Recent Accounting Pronouncements - Provision For Impairment (Details)	12 Months Ended
	Dec. 31, 2015 USD ($) item	Dec. 31, 2014 USD ($) item	Dec. 31, 2013 USD ($) item
Impairment Provisions
Total Provisions for impairment | $	$ 10,600,000	$ 4,600,000	$ 3,000,000
Number of impaired properties sold	7	9	7
Number of impaired properties held-for-sale	3
Number of impaired properties held-for-investment	4	2
Number of impaired properties disposed from other than sale	1
Provision for impairment, income from discontinued operations | $			$ 2,700,000
Provision for impairment, amount included in income from continuing operations | $		$ 4,100,000
Automotive parts
Impairment Provisions
Number of properties impaired			1
Automotive service
Impairment Provisions
Number of properties impaired			1
Provision for impairment, amount included in income from continuing operations | $			$ 290,000
Child care
Impairment Provisions
Number of properties impaired			2
Grocery stores
Impairment Provisions
Provisions for impairment | $		$ 510,000
Number of properties impaired		1	1
Health and Fitness
Impairment Provisions
Number of properties impaired	1
Pet supplies and services
Impairment Provisions
Number of properties impaired	1		1
Restaurants - casual dining industry
Impairment Provisions
Number of properties impaired	11	6	2
Restaurants - casual dining industry | Crest Net Lease, Inc. (Crest)
Impairment Provisions
Provisions for impairment | $			$ 308,000
Number of impaired properties sold			1
Convenience stores
Impairment Provisions
Number of properties impaired	1	1
Home furnishings
Impairment Provisions
Number of properties impaired		1
Consumer electronics
Impairment Provisions
Number of properties impaired		1
Home improvement
Impairment Provisions
Number of properties impaired		2
Other non-reportable segments
Impairment Provisions
Number of properties impaired	1