Notes Payable - Additional Information (Detail) $ in Thousands																		1 Months Ended	12 Months Ended
	Dec. 15, 2017 USD ($) Community	Dec. 01, 2017 USD ($)	Nov. 30, 2017 USD ($) Community	May 31, 2017 USD ($)	Jan. 31, 2017 USD ($) Community	Dec. 22, 2016 USD ($) Community	Dec. 15, 2016 USD ($) Community	Nov. 02, 2016 USD ($) Community	Sep. 30, 2016 USD ($) Community	Sep. 27, 2016 USD ($) Community	Sep. 23, 2016 USD ($) Community	Aug. 02, 2016 USD ($) Community	Jun. 15, 2016 USD ($) Community	May 31, 2016 USD ($)	May 03, 2016 USD ($)	Feb. 16, 2016 USD ($)	Jan. 26, 2016 USD ($)	Jul. 31, 2016 USD ($) Community	Dec. 31, 2017 USD ($) Community	Dec. 31, 2016 USD ($)	Dec. 31, 2015 Community
Debt Instrument [Line Items]
Senior housing communities operated by company | Community																			129
Deferred financing cost																			$ 14,000	$ 12,800
Accumulated amortization																			4,600	$ 3,000
Amortization expense																			1,700
Hartford Financial Services [Member]
Debt Instrument [Line Items]
Letters of credit remain outstanding																			3,900
Welltower, Inc. [Member]
Debt Instrument [Line Items]
Letters of credit remain outstanding																			6,700
HCP, Inc. [Member]
Debt Instrument [Line Items]
Letters of credit remain outstanding																			$ 2,900
Ventas [Member]
Debt Instrument [Line Items]
Acquisition of senior housing community | Community					4
Cincinnati, Ohio [Member]
Debt Instrument [Line Items]
Fixed interest rate								4.24%
Acquisition of senior housing community | Community								1
Springfield Massachusetts [Member]
Debt Instrument [Line Items]
Fixed interest rate									4.10%
Acquisition of senior housing community | Community									1
Kingwood Texas [Member]
Debt Instrument [Line Items]
Fixed interest rate										4.13%
Acquisition of senior housing community | Community										1
3.04% Insurance Financing Agreement [Member]
Debt Instrument [Line Items]
Insurance finance agreement, outstanding amount		$ 3,500
Debt instrument, fixed interest rate		3.04%
Debt instrument, repayment term		11 months
2.76% Insurance Financing Agreement [Member]
Debt Instrument [Line Items]
Insurance finance agreement, outstanding amount				$ 1,600
Debt instrument, fixed interest rate				2.76%
Debt instrument, repayment term				11 months
1.66%,10-Month Term Financing Agreement [Member]
Debt Instrument [Line Items]
Insurance finance agreement, outstanding amount					$ 800
Debt instrument, fixed interest rate					1.66%
Debt instrument, repayment term					10 months
2.16%,15-Month Term Financing Agreement [Member]
Debt Instrument [Line Items]
Insurance finance agreement, outstanding amount														$ 2,600
Debt instrument, fixed interest rate														2.16%
Debt instrument, repayment term														15 months
2.16%,11-Month Term Financing Agreement [Member]
Debt Instrument [Line Items]
Insurance finance agreement, outstanding amount														$ 1,500
Debt instrument, fixed interest rate														2.16%
Debt instrument, repayment term														11 months
5.71% [Member] | New York [Member] | Fannie Mae [Member]
Debt Instrument [Line Items]
Mortgage debt	$ 4,100
Fixed interest rate	5.71%
Senior housing communities operated by company | Community	1
Mortgage debt maturity	2025-06
Deferred financing cost	$ 200
5.49% [Member] | Ohio [Member] | Fannie Mae [Member]
Debt Instrument [Line Items]
Mortgage debt			$ 3,000
Fixed interest rate			5.49%
Senior housing communities operated by company | Community			1
Mortgage debt maturity			2023-01
Deferred financing cost			$ 100
Mortgage Loan [Member] | Ventas [Member]
Debt Instrument [Line Items]
Mortgage debt					$ 65,000
Deferred financing cost					$ 900
Debt instrument, repayment term					3 years
Acquisition price at a variable rate																			LIBOR
Deferred financing costs amortization period					3 years
Mortgage Loan [Member] | LIBOR [Member] | Ventas [Member]
Debt Instrument [Line Items]
Debt instrument variable interest rate					4.00%
5.84% [Member] | Michigan [Member] | Fannie Mae [Member]
Debt Instrument [Line Items]
Mortgage debt						$ 5,000
Fixed interest rate						5.84%
Senior housing communities operated by company | Community						1
Mortgage debt maturity						2026-04
Deferred financing cost						$ 100
5.81% [Member] | Indiana [Member] | Fannie Mae [Member]
Debt Instrument [Line Items]
Mortgage debt						$ 1,500
Fixed interest rate						5.81%
Senior housing communities operated by company | Community						1
Mortgage debt maturity						2025-12
Deferred financing cost						$ 45,000
5.72% [Member] | Virginia [Member] | Fannie Mae [Member]
Debt Instrument [Line Items]
Mortgage debt						$ 3,700
Fixed interest rate						5.72%
Senior housing communities operated by company | Community						1
Mortgage debt maturity						2024-09
Deferred financing cost						$ 100
5.53% [Member] | Ohio [Member] | Fannie Mae [Member]
Debt Instrument [Line Items]
Mortgage debt							$ 5,400
Fixed interest rate							5.53%
Senior housing communities operated by company | Community							1
Mortgage debt maturity							2025-04
Deferred financing cost							$ 100
4.24% [Member] | Cincinnati, Ohio [Member]
Debt Instrument [Line Items]
Mortgage debt								$ 22,000
Fixed interest rate								4.24%
Deferred financing cost								$ 200
Deferred financing costs amortization period								10 years
Term period of mortgage loans								10 years
Term period of principal amortized								30 years
4.10% [Member] | Springfield Massachusetts [Member]
Debt Instrument [Line Items]
Mortgage debt									$ 20,300
Fixed interest rate									4.10%
Deferred financing cost									$ 200
Deferred financing costs amortization period									10 years
Term period of mortgage loans									10 years
Term period of principal amortized									30 years
4.13% [Member] | Kingwood Texas [Member]
Debt Instrument [Line Items]
Mortgage debt										$ 13,000
Fixed interest rate										4.13%
Deferred financing cost										$ 200
Deferred financing costs amortization period										15 years
Term period of mortgage loans										15 years
Term period of principal amortized										30 years
4.85% [Member] | Indiana [Member] | Fannie Mae [Member]
Debt Instrument [Line Items]
Mortgage debt											$ 3,500
Fixed interest rate											4.85%
Senior housing communities operated by company | Community											1
Mortgage debt maturity											2022-04
Deferred financing cost											$ 100
4.85% [Member] | Texas [Member] | Fannie Mae [Member]
Debt Instrument [Line Items]
Mortgage debt											$ 3,800
Fixed interest rate											4.85%
Senior housing communities operated by company | Community											1
Mortgage debt maturity											2022-05
Deferred financing cost											$ 100
4.97% [Member] | Texas [Member] | Fannie Mae [Member]
Debt Instrument [Line Items]
Mortgage debt												$ 2,100
Fixed interest rate												4.97%
Senior housing communities operated by company | Community												1
Mortgage debt maturity												2022-04
Deferred financing cost												$ 100
Variable Interest Rate LIBOR Plus 4.50% Loan [Member] | Berkadia Commercial Mortgage LLC [Member]
Debt Instrument [Line Items]
Senior housing communities operated by company | Community																		1
Deferred financing cost																		$ 30,000
Acquisition price at a variable rate																			LIBOR plus 4.50%
Debt instrument variable interest rate																		4.50%
Deferred financing costs amortization period																		25 years
Debt instrument maturity date																		Jul. 10, 2018
4.98% [Member] | Fannie Mae [Member]
Debt Instrument [Line Items]
Mortgage debt													$ 16,900
Fixed interest rate													4.98%
Mortgage debt maturity													2024-07
Deferred financing cost													$ 500
4.98% [Member] | Ohio [Member] | Fannie Mae [Member]
Debt Instrument [Line Items]
Senior housing communities operated by company | Community													2
4.98% [Member] | Texas [Member] | Fannie Mae [Member]
Debt Instrument [Line Items]
Senior housing communities operated by company | Community													4
4.98% [Member] | Missouri [Member] | Fannie Mae [Member]
Debt Instrument [Line Items]
Senior housing communities operated by company | Community													1
4.25% [Member] | Indianapolis Transaction [Member]
Debt Instrument [Line Items]
Mortgage debt															$ 2,600
Fixed interest rate															4.25%
Term period of mortgage loans															10 years
Term period of principal amortized															30 years
Acquisition of senior housing community | Community																					1
4.38% [Member] | Pensacola Transaction [Member]
Debt Instrument [Line Items]
Mortgage debt																$ 35,000
Fixed interest rate																4.38%
Deferred financing cost																$ 400
Deferred financing costs amortization period																10 years
Term period of mortgage loans																10 years
Term period of principal amortized																30 years
4.50% [Member] | Pine Ridge Transaction [Member]
Debt Instrument [Line Items]
Mortgage debt																	$ 11,300
Fixed interest rate																	4.50%
Deferred financing cost																	$ 200
Deferred financing costs amortization period																	10 years
Term period of mortgage loans																	10 years
Term period of principal amortized																	30 years