Aggregate Allocation of Purchase Price (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Transaction to Real Estate Investments [Line Items]
Total purchase price	$ 190,743
Real Estate Investment
Transaction to Real Estate Investments [Line Items]
Total purchase price	176,519
TENNESSEE
Transaction to Real Estate Investments [Line Items]
Total purchase price	19,000
TENNESSEE | Real Estate Investment
Transaction to Real Estate Investments [Line Items]
Total purchase price	16,812
VIRGINIA
Transaction to Real Estate Investments [Line Items]
Total purchase price	17,743
VIRGINIA | Real Estate Investment
Transaction to Real Estate Investments [Line Items]
Total purchase price	18,440
Land
Transaction to Real Estate Investments [Line Items]
Total purchase price	31,478
Land | TENNESSEE
Transaction to Real Estate Investments [Line Items]
Total purchase price	3,503
Land | VIRGINIA
Transaction to Real Estate Investments [Line Items]
Total purchase price	6,394
Building
Transaction to Real Estate Investments [Line Items]
Total purchase price	119,955
Building | TENNESSEE
Transaction to Real Estate Investments [Line Items]
Total purchase price	11,960
Building | VIRGINIA
Transaction to Real Estate Investments [Line Items]
Total purchase price	10,862
Site Improvements
Transaction to Real Estate Investments [Line Items]
Total purchase price	15,485
Site Improvements | TENNESSEE
Transaction to Real Estate Investments [Line Items]
Total purchase price	1,349
Site Improvements | VIRGINIA
Transaction to Real Estate Investments [Line Items]
Total purchase price	1,184
Tenant Improvements [Member]
Transaction to Real Estate Investments [Line Items]
Total purchase price	9,601
Leaseholds and Leasehold Improvements [Member]
Transaction to Real Estate Investments [Line Items]
Total purchase price	30,061
Leaseholds and Leasehold Improvements [Member] | TENNESSEE
Transaction to Real Estate Investments [Line Items]
Total purchase price	4,288
Leaseholds and Leasehold Improvements [Member] | VIRGINIA
Transaction to Real Estate Investments [Line Items]
Total purchase price	3,218
Above Market Lease [Member]
Transaction to Real Estate Investments [Line Items]
Total purchase price	5,463
Below Market Lease Liabilities [Member]
Transaction to Real Estate Investments [Line Items]
Total purchase price	21,300
Below Market Lease Liabilities [Member] | TENNESSEE
Transaction to Real Estate Investments [Line Items]
Total purchase price	2,100
Below Market Lease Liabilities [Member] | VIRGINIA
Transaction to Real Estate Investments [Line Items]
Total purchase price	3,915
Joint Venture Agreement [Member]
Transaction to Real Estate Investments [Line Items]
Total purchase price	154,000
Joint Venture Agreement [Member] | Real Estate Investment
Transaction to Real Estate Investments [Line Items]
Total purchase price	141,267
Joint Venture Agreement [Member] | Land
Transaction to Real Estate Investments [Line Items]
Total purchase price	21,581
Joint Venture Agreement [Member] | Building
Transaction to Real Estate Investments [Line Items]
Total purchase price	97,133
Joint Venture Agreement [Member] | Site Improvements
Transaction to Real Estate Investments [Line Items]
Total purchase price	12,952
Joint Venture Agreement [Member] | Tenant Improvements [Member]
Transaction to Real Estate Investments [Line Items]
Total purchase price	9,601
Joint Venture Agreement [Member] | Leaseholds and Leasehold Improvements [Member]
Transaction to Real Estate Investments [Line Items]
Total purchase price	22,555
Joint Venture Agreement [Member] | Above Market Lease [Member]
Transaction to Real Estate Investments [Line Items]
Total purchase price	5,463
Joint Venture Agreement [Member] | Below Market Lease Liabilities [Member]
Transaction to Real Estate Investments [Line Items]
Total purchase price	$ 15,285