Real Estate under Development with Third-Party Developers (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)
Real Estate Properties [Line Items]
Real Estate Development Costs Incurred	$ 97,164	[1]
(Unaudited) Remaining Development Budget	$ 47,031	[2]
Welbrook Senior Living Grand Junction (Grand Junction, CO)
Real Estate Properties [Line Items]
Developer	Embree Asset Group, Inc.
Real Estate Development Costs Incurred	$ 12,894	[1]
(Unaudited) Remaining Development Budget	$ 1,888	[2]
Waterstone on Augusta (Greenville, SC)
Real Estate Properties [Line Items]
Developer	T&D Greenville, LLC
Real Estate Development Costs Incurred	$ 24,155	[1]
(Unaudited) Remaining Development Budget	$ 5,046	[2]
Wellmore of Lexington (Lexington, SC)
Real Estate Properties [Line Items]
Developer	Maxwell Group, Inc.
Real Estate Development Costs Incurred	$ 38,972	[1]
(Unaudited) Remaining Development Budget	$ 19,984	[2]
Dogwood Forest of Grayson (Grayson, GA)
Real Estate Properties [Line Items]
Developer	Solomon Development Services, LLC
Real Estate Development Costs Incurred	$ 17,345	[1]
(Unaudited) Remaining Development Budget	$ 12,933	[2]
Tranquillity at Fredericktowne (Frederick, MD)
Real Estate Properties [Line Items]
Developer	Capital Health Partners
Real Estate Development Costs Incurred	$ 1,407	[1]
(Unaudited) Remaining Development Budget	$ 4,542	[2]
Brookridge Heights Assisted Living & Memory Care (Marquette, MI)
Real Estate Properties [Line Items]
Developer	Capital Health Partners
Real Estate Development Costs Incurred	$ 2,391	[1]
(Unaudited) Remaining Development Budget	$ 2,638	[2]

[1] This amount represents land and total capitalized costs for GAAP purposes for the acquisition, development and construction of the seniors housing community or post-acute care facility as of December 31, 2016. Amounts include investment services fees, asset management fees, interest expense and other costs capitalized during the development period.

[2] This amount includes preleasing and marketing costs which will be expensed as incurred.