Real Estate Investments - Schedule of Real Estate Property Investments (Details) $ in Thousands	Dec. 31, 2017 USD ($) mortgage_note_receivable real_estate_property	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	86
Land and land improvements	$ 44,419	$ 29,884
Buildings, Improvements, and Lease Intangibles	343,955	222,755
Personal property	112	97
Total real estate properties	388,486	252,736
Accumulated Depreciation	$ 36,136	18,404
Number of mortgage note receivables | mortgage_note_receivable	1
Mortgage note receivable, net	$ 10,633	$ 10,786	$ 10,897	$ 0
Value of real estate property investments and mortgages	$ 399,119
Medical office buildings [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	32
Land and land improvements	$ 19,318
Buildings, Improvements, and Lease Intangibles	123,907
Personal property	0
Total real estate properties	143,225
Accumulated Depreciation	$ 16,886
Medical office buildings [Member] | Florida [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	5
Land and land improvements	$ 4,608
Buildings, Improvements, and Lease Intangibles	29,235
Total real estate properties	33,843
Accumulated Depreciation	$ 2,493
Medical office buildings [Member] | Iowa [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	1
Land and land improvements	$ 2,241
Buildings, Improvements, and Lease Intangibles	8,991
Total real estate properties	11,232
Accumulated Depreciation	$ 1,148
Medical office buildings [Member] | Virginia [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	1
Land and land improvements	$ 369
Buildings, Improvements, and Lease Intangibles	4,649
Total real estate properties	5,018
Accumulated Depreciation	$ 233
Medical office buildings [Member] | Illinois [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	2
Land and land improvements	$ 1,134
Buildings, Improvements, and Lease Intangibles	11,823
Total real estate properties	12,957
Accumulated Depreciation	$ 1,589
Medical office buildings [Member] | Kansas [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	2
Land and land improvements	$ 1,427
Buildings, Improvements, and Lease Intangibles	10,497
Total real estate properties	11,924
Accumulated Depreciation	$ 2,429
Medical office buildings [Member] | Ohio [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	5
Land and land improvements	$ 3,167
Buildings, Improvements, and Lease Intangibles	23,526
Total real estate properties	26,693
Accumulated Depreciation	$ 3,431
Medical office buildings [Member] | Other States [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	13
Land and land improvements	$ 3,276
Buildings, Improvements, and Lease Intangibles	22,697
Total real estate properties	25,973
Accumulated Depreciation	$ 2,279
Medical office buildings [Member] | Texas [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	3
Land and land improvements	$ 3,096
Buildings, Improvements, and Lease Intangibles	12,489
Total real estate properties	15,585
Accumulated Depreciation	$ 3,284
Physician clinics [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	17
Land and land improvements	$ 7,474
Buildings, Improvements, and Lease Intangibles	41,664
Personal property	0
Total real estate properties	49,138
Accumulated Depreciation	$ 5,605
Physician clinics [Member] | Florida [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	3
Land and land improvements	$ 0
Buildings, Improvements, and Lease Intangibles	5,950
Total real estate properties	5,950
Accumulated Depreciation	$ 512
Physician clinics [Member] | Illinois [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	2
Land and land improvements	$ 2,615
Buildings, Improvements, and Lease Intangibles	6,354
Total real estate properties	8,969
Accumulated Depreciation	$ 87
Physician clinics [Member] | Kansas [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	3
Land and land improvements	$ 1,638
Buildings, Improvements, and Lease Intangibles	10,899
Total real estate properties	12,537
Accumulated Depreciation	$ 1,981
Physician clinics [Member] | Other States [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	9
Land and land improvements	$ 3,221
Buildings, Improvements, and Lease Intangibles	18,461
Total real estate properties	21,682
Accumulated Depreciation	$ 3,025
Surgical centers and hospitals [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	13
Land and land improvements	$ 7,419
Buildings, Improvements, and Lease Intangibles	72,846
Personal property	0
Total real estate properties	80,265
Accumulated Depreciation	$ 7,731
Surgical centers and hospitals [Member] | Arizona [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	2
Land and land improvements	$ 576
Buildings, Improvements, and Lease Intangibles	5,389
Total real estate properties	5,965
Accumulated Depreciation	$ 1,000
Surgical centers and hospitals [Member] | Florida [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	1
Land and land improvements	$ 271
Buildings, Improvements, and Lease Intangibles	7,017
Total real estate properties	7,288
Accumulated Depreciation	$ 233
Surgical centers and hospitals [Member] | Illinois [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	1
Land and land improvements	$ 2,183
Buildings, Improvements, and Lease Intangibles	5,410
Total real estate properties	7,593
Accumulated Depreciation	$ 740
Surgical centers and hospitals [Member] | Indiana [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	1
Land and land improvements	$ 523
Buildings, Improvements, and Lease Intangibles	14,405
Total real estate properties	14,928
Accumulated Depreciation	$ 360
Surgical centers and hospitals [Member] | Louisiana [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	1
Land and land improvements	$ 1,683
Buildings, Improvements, and Lease Intangibles	21,353
Total real estate properties	23,036
Accumulated Depreciation	$ 577
Surgical centers and hospitals [Member] | Michigan [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	2
Land and land improvements	$ 628
Buildings, Improvements, and Lease Intangibles	8,272
Total real estate properties	8,900
Accumulated Depreciation	$ 1,960
Surgical centers and hospitals [Member] | Other States [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	5
Land and land improvements	$ 1,555
Buildings, Improvements, and Lease Intangibles	11,000
Total real estate properties	12,555
Accumulated Depreciation	$ 2,861
Specialty centers [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	17
Land and land improvements	$ 4,667
Buildings, Improvements, and Lease Intangibles	47,058
Personal property	0
Total real estate properties	51,725
Accumulated Depreciation	$ 4,637
Specialty centers [Member] | Alabama [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	3
Land and land improvements	$ 415
Buildings, Improvements, and Lease Intangibles	4,417
Total real estate properties	4,832
Accumulated Depreciation	$ 1,295
Specialty centers [Member] | NEVADA
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	1
Land and land improvements	$ 276
Buildings, Improvements, and Lease Intangibles	4,402
Total real estate properties	4,678
Accumulated Depreciation	$ 273
Specialty centers [Member] | Illinois [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	2
Land and land improvements	$ 2,057
Buildings, Improvements, and Lease Intangibles	19,575
Total real estate properties	21,632
Accumulated Depreciation	$ 215
Specialty centers [Member] | Other States [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	11
Land and land improvements	$ 1,919
Buildings, Improvements, and Lease Intangibles	18,664
Total real estate properties	20,583
Accumulated Depreciation	$ 2,854
Behavioral facilities [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	6
Land and land improvements	$ 5,541
Buildings, Improvements, and Lease Intangibles	56,469
Personal property	0
Total real estate properties	62,010
Accumulated Depreciation	$ 1,153
Behavioral facilities [Member] | Illinois [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	1
Land and land improvements	$ 1,300
Buildings, Improvements, and Lease Intangibles	18,803
Total real estate properties	20,103
Accumulated Depreciation	$ 745
Behavioral facilities [Member] | Indiana [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	2
Land and land improvements	$ 1,126
Buildings, Improvements, and Lease Intangibles	6,040
Total real estate properties	7,166
Accumulated Depreciation	$ 156
Behavioral facilities [Member] | Other States [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	2
Land and land improvements	$ 977
Buildings, Improvements, and Lease Intangibles	8,729
Total real estate properties	9,706
Accumulated Depreciation	$ 100
Behavioral facilities [Member] | West Virginia [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	1
Land and land improvements	$ 2,138
Buildings, Improvements, and Lease Intangibles	22,897
Total real estate properties	25,035
Accumulated Depreciation	$ 152
Corporate Property [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	0
Land and land improvements	$ 0
Buildings, Improvements, and Lease Intangibles	2,011
Personal property	112
Total real estate properties	2,123
Accumulated Depreciation	$ 124
Total Properties [Member]
Real Estate Properties [Line Items]
Number of Properties | real_estate_property	85
Land and land improvements	$ 44,419
Buildings, Improvements, and Lease Intangibles	343,955
Personal property	112
Total real estate properties	388,486
Accumulated Depreciation	$ 36,136