Real Estate and Intangibles - Fair Values of Assets Acquired and Liabilities Assumed (Detail) - Operating Properties Acquired [Member] - D E A Sterling V A F D A College Park M D And Various G S A Portland O R J S C Scffolk F B I New Orleans Member $ in Thousands	Jun. 30, 2021 USD ($)
Business Acquisition [Line Items]
Total real estate	$ 99,817
Total intangible assets	11,605
Total intangible liabilities	(1)
Purchase price	111,421
Real Estate Investment [Member]
Business Acquisition [Line Items]
Land	5,623
Building	87,067
Acquired tenant improvements	7,127
In-place leases [Member]
Business Acquisition [Line Items]
Total intangible assets	8,539
Acquired Leasing Commissions [Member]
Business Acquisition [Line Items]
Total intangible assets	2,765
Above Market Leases [Member]
Business Acquisition [Line Items]
Total intangible assets	301
Below Market Leases [Member]
Business Acquisition [Line Items]
Total intangible liabilities	$ (1)