Indebtedness - Additional Information (Detail)	1 Months Ended	12 Months Ended
	Nov. 30, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2014 USD ($) Extension
Debt Instrument [Line Items]
Line of credit facility extension period			12 months
After Modification
Debt Instrument [Line Items]
Aggregate maximum principal amount available for borrowing		$ 445,000,000	$ 700,000,000
Revolving Credit Facility
Debt Instrument [Line Items]
Aggregate maximum principal amount available for borrowing			$ 230,000,000
Term of credit facility			36 months
Line of credit facility, initial maturity			2017-12
Line of credit facility, extended maturity			2019-12
Number of extension options available | Extension			2
Line of credit facility extension period			12 months
Revolving Credit Facility | 30-day LIBOR | Minimum
Debt Instrument [Line Items]
Fees paid range on unused commitments, percentage			0.15%
Revolving Credit Facility | 30-day LIBOR | Maximum
Debt Instrument [Line Items]
Fees paid range on unused commitments, percentage			0.25%
Term Loan Credit Facility
Debt Instrument [Line Items]
Aggregate maximum principal amount available for borrowing			$ 175,000,000
Term of credit facility			50 months
Line of credit facility, initial maturity			2019-02
Line of credit facility, extended maturity			2020-02
Number of extension options available | Extension			1
Second Term Loan Facility
Debt Instrument [Line Items]
Line of credit facility, initial maturity	2020-11
Second Term Loan Facility | 30-day LIBOR
Debt Instrument [Line Items]
Aggregate maximum principal amount available for borrowing	$ 250,000,000
Term of credit facility	60 months
Second Term Loan Facility | After Modification | 30-day LIBOR
Debt Instrument [Line Items]
Aggregate maximum principal amount available for borrowing	$ 350,000,000	$ 275,000,000
Credit facilities
Debt Instrument [Line Items]
Description of covenants		The Credit Facilities contain affirmative, negative, and financial covenants which are customary for loans of this type, including (but not limited to): (i) maximum leverage, (ii) minimum fixed charge coverage ratio, (iii) minimum consolidated net worth, (iv) restrictions on payments of cash distributions except if required by REIT requirements, (v) maximum secured indebtedness, (vi) maximum secured recourse debt, (vii) minimum unsecured interest coverage and (viii) limitations on certain types of investments and with respect to the pool of properties supporting borrowings under the Credit Facilities, minimum debt service coverage ratio, minimum weighted average occupancy, and remaining lease terms, as well as property type, MSA, operator, and asset value concentration limits. The limitations on distributions include a limitation on the extent of allowable distributions, which are not to exceed the greater of 95% of adjusted FFO (as defined per the Credit Facilities) and the minimum amount of distributions required to maintain the Company’s REIT status. As of December 31, 2016, the Company was in compliance with all financial covenants and ratios.