Summary of Significant Accounting Policies - Additional Information (Detail)							12 Months Ended
	Nov. 18, 2016 shares	Mar. 28, 2016 shares	Aug. 18, 2015 shares	Dec. 10, 2014 USD ($) shares	Oct. 31, 2014	Oct. 17, 2014 USD ($) $ / shares	Dec. 31, 2016 USD ($) facility segment	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Property, Plant and Equipment [Line Items]
Number of independent living facilities operated immediately following the Spin-Off | facility							3
Accumulated amortization of deferred financing costs							$ 4,200,000	$ 3,300,000
Reserve against receivables							0	0
Dividends payable							$ 11,075,000	7,704,000
Dividend, payable date							Jan. 15, 2015
Dividend, record date							Dec. 31, 2014
Issuance of common stock, net (in shares) | shares	6,330,000	9,780,000	16,330,000
Stock-based compensation expense							$ 1,546,000	$ 1,522,000	$ 154,000
Number of reportable segments | segment							1
Interest Rate Swap [Member]
Property, Plant and Equipment [Line Items]
Interest rate swap outstanding							$ 0
Special Dividend [Member]
Property, Plant and Equipment [Line Items]
Dividend, declared date						Oct. 17, 2014	Oct. 17, 2014
Dividends payable						$ 132,000,000
Dividend payable per share (in usd per share) | $ / shares						$ 5.88
Dividend, payable date				Dec. 10, 2014			Dec. 10, 2014
Dividend, record date					Oct. 31, 2014		Oct. 31, 2014
Cash portion of dividend				$ 33,000,000
Stock portion of dividend				$ 99,000,000
Issuance of common stock, net (in shares) | shares				8,974,249
Lease Agreements [Member]
Property, Plant and Equipment [Line Items]
Remaining contractual payments							$ 400,000