Condensed Combined Statement of Income for Limited Liabilities Accounted for under Equity Method (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Equity Method Investments And Joint Ventures [Abstract]
Revenues		$ 3,776	$ 3,638	$ 11,437	$ 10,799
Operating expenses		1,329	1,461	4,025	4,194
Depreciation and amortization		646	634	1,910	1,788
Interest, net		636	656	1,928	1,907
Net income		1,165	887	3,574	2,910
Our share of net income	[1]	$ 1,110	$ 561	$ 3,396	$ 1,826

[1] Our share of net income for the three and nine months ended September 30, 2016 includes approximately $291,000 and $880,000, respectively, of interest income earned by us on an advance made to Arlington Medical Properties, LLC (advance balance payable to us is approximately $21.8 million as of September 30, 2016). There were no advances outstanding during the first nine months of 2015, therefore there was no interest income earned by us for the three and nine months ended September 30, 2015. Also, as mentioned above, effective February 1, 2016, we purchased an additional 10% of the ownership interest in Arlington Medical Properties, LLC thereby increasing our ownership interest to 85%, from 75% previously.