Investments in Real Estate and Real Estate Under Construction - Schedule of Acquired Properties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	$ 310,128	$ 491,102
Land and Land Estate	29,085	33,799
Buildings and building improvements	250,945	387,222
Lease in-place Value	32,113	$ 70,081
Below Market Lease	$ (2,015)
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 7 months 6 days	16 years 9 months 18 days
Leases, Acquired-in-Place, Market Adjustment [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Weighted-average life of intangible assets (years)	16 years 1 month 6 days
Other Property [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
Buildings and building improvements		11,753
Lease in-place Value		401
Office Property [Member] | Lake Jackson, Texas [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	$ 78,484
Land and Land Estate	4,357
Buildings and building improvements	74,127
Lease in-place Value	0
Below Market Lease	0
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
Buildings and building 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
Buildings and building improvements		88,021
Lease in-place Value		14,192
Industrial Property [Member] | Detroit, Michigan [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	29,697
Land and Land Estate	1,133
Buildings and building improvements	25,009
Lease in-place Value	3,555
Below Market Lease	0
Industrial Property [Member] | Anderson, South Carolina [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	61,347
Land and Land Estate	4,663
Buildings and building improvements	45,011
Lease in-place Value	11,673
Below Market Lease	0
Industrial Property [Member] | Wilsonville, Oregon [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	43,100
Land and Land Estate	6,815
Buildings and building improvements	32,380
Lease in-place Value	5,920
Below Market Lease	(2,015)
Industrial Property [Member] | Romeoville, Illinois [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	52,700
Land and Land Estate	7,524
Buildings and building improvements	40,167
Lease in-place Value	5,009
Below Market Lease	0
Industrial Property [Member] | Edwardsville, Illinois [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	44,800
Land and Land Estate	4,593
Buildings and building improvements	34,251
Lease in-place Value	5,956
Below Market Lease	$ 0
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
Buildings and building 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
Buildings and building 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
Buildings and building 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
Buildings and building 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
Buildings and building 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
Buildings and building improvements		126,947
Lease in-place Value		$ 23,760
LCIF [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Weighted-average life of intangible assets (years)	14 years 10 months 24 days	19 years 9 months 18 days
LCIF [Member] | Industrial Property [Member] | Romeoville, Illinois [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	$ 52,700
Land and Land Estate	7,524
Buildings and building improvements	40,167
Lease in-place Value	$ 5,009
LCIF [Member] | 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
Buildings and building improvements		126,947
Lease in-place Value		$ 23,760