Summary of Acquisitions of Real Estate Held for Investment (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Transaction to Real Estate Investments [Line Items]
Purchase Price	$ 190,743
TENNESSEE
Transaction to Real Estate Investments [Line Items]
Purchase Price	19,000
TENNESSEE | Single Tenant Properties [Member]
Transaction to Real Estate Investments [Line Items]
Date of Acquisition	Apr. 30, 2014
Purchase Price	19,000
Remaining Lease Term (Years)	8 years	[1]
VIRGINIA
Transaction to Real Estate Investments [Line Items]
Purchase Price	17,743
VIRGINIA | Multi Tenant Properties [Member]
Transaction to Real Estate Investments [Line Items]
Date of Acquisition	Jun. 30, 2014
Purchase Price	17,743
Remaining Lease Term (Years)	7 years	[1]
New York, Ohio and Georgia [Member] | Multi Tenant Properties [Member]
Transaction to Real Estate Investments [Line Items]
Date of Acquisition	Nov. 30, 2014
Purchase Price	$ 154,000
Remaining Lease Term (Years)	4 years 7 months 6 days	[1]

[1] Does not include extension options.