Investments in Real Estate and Real Estate Under Construction - Schedule of Acquired Properties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	$ 491,102	$ 212,313
Land and Land Estate	33,799	33,621
Building and Improvements	387,222	142,247
Lease in-place Value	$ 70,081	$ 36,445
Leases, Acquired-in-Place [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Weighted-average life of intangible assets (years)	16 years 9 months 18 days	37 years 6 months
Land / Infrastructure [Member] | Venice, Florida [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	$ 16,850
Land and Land Estate	4,696
Building and Improvements	11,753
Lease in-place Value	401
Office Property [Member] | Auburn Hill, Michigan [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	40,025
Land and Land Estate	4,416
Building and Improvements	30,012
Lease in-place Value	5,597
Office Property [Member] | Richmond, Virginia [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	109,544
Land and Land Estate	7,331
Building and Improvements	88,021
Lease in-place Value	14,192
Office Property [Member] | Parachute, Colorado [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis		$ 13,928
Land and Land Estate		1,400
Building and Improvements		10,751
Lease in-place Value		1,777
Office Property [Member] | Rock Hill, South Carolina [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis		24,715
Land and Land Estate		1,601
Building and Improvements		18,989
Lease in-place Value		4,125
Industrial Property [Member] | Houston, Texas [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	28,650
Land and Land Estate	4,674
Building and Improvements	19,540
Lease in-place Value	4,436
Industrial Property [Member] | Brookshire, Texas [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	22,450
Land and Land Estate	2,388
Building and Improvements	16,614
Lease in-place Value	3,448
Industrial Property [Member] | Canton, Mississippi [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	89,300
Land and Land Estate	5,077
Building and Improvements	71,289
Lease in-place Value	12,934
Industrial Property [Member] | Thomson, Georgia [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	10,144
Land and Land Estate	909
Building and Improvements	7,746
Lease in-place Value	1,489
Industrial Property [Member] | Oak Creek, Wisconsin [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	22,139
Land and Land Estate	3,015
Building and Improvements	15,300
Lease in-place Value	3,824
Industrial Property [Member] | Richland, Washington [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	152,000
Land and Land Estate	1,293
Building and Improvements	126,947
Lease in-place Value	$ 23,760
Industrial Property [Member] | Rantoul, Illinois [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis		41,277
Land and Land Estate		1,304
Building and Improvements		32,562
Lease in-place Value		7,411
Industrial Property [Member] | Lewisburg, Tennessee [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis		13,320
Land and Land Estate		173
Building and Improvements		10,865
Lease in-place Value		2,282
Industrial Property [Member] | North Las Vegas, Nevada [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis		28,249
Land and Land Estate		3,244
Building and Improvements		21,444
Lease in-place Value		3,561
Industrial Property [Member] | Bingen, Washington [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis		20,391
Land and Land Estate		0
Building and Improvements		18,075
Lease in-place Value		2,316
Industrial Property [Member] | Anniston, Alabama [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis		20,907
Land and Land Estate		1,201
Building and Improvements		16,771
Lease in-place Value		2,935
Land [Member] | New York, New York [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis		30,426
Land and Land Estate		22,000
Building and Improvements		0
Lease in-place Value		8,426
Rehabilitation Hospital [Member] | Vineland, New Jersey [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis		19,100
Land and Land Estate		2,698
Building and Improvements		12,790
Lease in-place Value		$ 3,612