Acquisitions of Properties (Detail) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended
		Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Purchase Price			$ 28,588	$ 880,873
Cobalt Rehabilitation Hospital New Orleans
Business Acquisition [Line Items]
Location			New Orleans, LA
Structure			Triple-net Lease
Date Acquired			Oct. 19, 2016
Purchase Price			$ 28,588
North Carolina Specialty Hospital
Business Acquisition [Line Items]
Location			Durham, NC
Structure			Modified Lease
Date Acquired				Jun. 29, 2015
Purchase Price				$ 31,830
Novi Orthopaedic Center
Business Acquisition [Line Items]
Location			Novi, MI
Structure			Modified Lease
Date Acquired				Feb. 13, 2015
Purchase Price	[1]			$ 30,500
UT Cancer Institute Building
Business Acquisition [Line Items]
Location			Knoxville, TN
Structure			Modified Lease
Date Acquired				Feb. 20, 2015
Purchase Price				$ 33,660
Bend Memorial Clinic MOB
Business Acquisition [Line Items]
Location			Bend, OR
Structure			Modified Lease
Date Acquired				May 11, 2015
Purchase Price	[1]			$ 36,000
Stoneterra Medical Plaza
Business Acquisition [Line Items]
Location			San Antonio, TX
Structure			Modified Lease
Date Acquired				May 29, 2015
Purchase Price	[1]			$ 15,050
Triangle Orthopaedic Durham
Business Acquisition [Line Items]
Location			Durham, NC
Structure			Modified Lease
Date Acquired				Jun. 29, 2015
Purchase Price				$ 21,275
Triangle Orthopaedic Oxford
Business Acquisition [Line Items]
Location			Oxford, NC
Structure			Modified Lease
Date Acquired				Jun. 29, 2015
Purchase Price				$ 4,728
Triangle Orthopaedic Chapel Hill
Business Acquisition [Line Items]
Location			Chapel Hill, NC
Structure			Modified Lease
Date Acquired				Jun. 29, 2015
Purchase Price				$ 3,258
Triangle Orthopaedic Roxboro
Business Acquisition [Line Items]
Location			Roxboro, NC
Structure			Modified Lease
Date Acquired				Jun. 29, 2015
Purchase Price				$ 2,067
Doctor's Park Building B
Business Acquisition [Line Items]
Location			Chula Vista, CA ("San Diego")
Structure			Modified Lease
Date Acquired				Jun. 30, 2015
Purchase Price	[1]			$ 5,000
Doctor's Park Building C
Business Acquisition [Line Items]
Location			Chula Vista, CA ("San Diego")
Structure			Modified Lease
Date Acquired				Jun. 30, 2015
Purchase Price	[1]			$ 10,000
540 New Waverly Place
Business Acquisition [Line Items]
Location			Cary, NC ("Raleigh")
Structure			Modified Lease
Date Acquired				Jul. 20, 2015
Purchase Price	[1]			$ 15,000
MedHelp
Business Acquisition [Line Items]
Location			Birmingham, AL
Structure			Modified Lease
Date Acquired				Jul. 31, 2015
Purchase Price	[1]			$ 15,000
Patriot Professional Center
Business Acquisition [Line Items]
Location			Frederick, MD ("Baltimore")
Structure			Modified Lease
Date Acquired				Jul. 31, 2015
Purchase Price	[1]			$ 16,950
Liberty Professional Center
Business Acquisition [Line Items]
Location			Frederick, MD ("Baltimore")
Structure			Modified Lease
Date Acquired				Jul. 31, 2015
Purchase Price	[1]			$ 7,300
Broadway Medical Plaza 1
Business Acquisition [Line Items]
Location			Columbia, MO
Structure			Modified Lease
Date Acquired				Aug. 21, 2015
Purchase Price	[1]			$ 10,700
Broadway Medical Plaza 2
Business Acquisition [Line Items]
Location			Columbia, MO
Structure			Modified Lease
Date Acquired				Aug. 21, 2015
Purchase Price	[1]			$ 13,100
Broadway Medical Plaza 4
Business Acquisition [Line Items]
Location			Columbia, MO
Structure			Modified Lease
Date Acquired				Aug. 21, 2015
Purchase Price	[1]			$ 14,200
Center One
Business Acquisition [Line Items]
Location			Jacksonville, FL
Structure			Modified Lease
Date Acquired				Nov. 30, 2015
Purchase Price	[1]			$ 34,362
Red Bank Professional Office Building
Business Acquisition [Line Items]
Location			Cincinnati, OH
Structure			Modified Lease
Date Acquired				Dec. 14, 2015
Purchase Price	[1]			$ 10,610
Siena Pavilion IV
Business Acquisition [Line Items]
Location			Henderson, NV ("Las Vegas")
Structure			Modified Lease
Date Acquired				Dec. 18, 2015
Purchase Price				$ 6,990
Siena Pavilion V
Business Acquisition [Line Items]
Location			Henderson, NV ("Las Vegas")
Structure			Modified Lease
Date Acquired				Dec. 18, 2015
Purchase Price				$ 27,859
Siena Pavilion VI
Business Acquisition [Line Items]
Location			Henderson, NV ("Las Vegas")
Structure			Modified Lease
Date Acquired				Dec. 18, 2015
Purchase Price				$ 19,474
Cobalt Rehabilitation Hospital Surprise
Business Acquisition [Line Items]
Location			Surprise, AZ ("Phoenix")
Structure			Triple-net Lease
Date Acquired				Dec. 30, 2015
Purchase Price	[1]			$ 23,660
Fieldstone Memory Care
Business Acquisition [Line Items]
Location			Yakima, WA
Structure			Managed
Date Acquired				Mar. 31, 2015
Purchase Price		$ 12,400		$ 12,400	[1]
Primrose Retirement Community of Anderson
Business Acquisition [Line Items]
Location			Anderson, IN ("Muncie")
Structure			Triple-net Lease
Date Acquired				May 29, 2015
Purchase Price				$ 21,086
Primrose Retirement Community of Lancaster
Business Acquisition [Line Items]
Location			Lancaster, OH ("Columbus")
Structure			Triple-net Lease
Date Acquired				May 29, 2015
Purchase Price				$ 25,657
Primrose Retirement Community of Wausau
Business Acquisition [Line Items]
Location			Wausau, WI ("Green Bay")
Structure			Triple-net Lease
Date Acquired				May 29, 2015
Purchase Price				$ 20,307
Superior Residences of Panama City
Business Acquisition [Line Items]
Location			Panama City Beach, FL
Structure			Managed
Date Acquired				Jul. 15, 2015
Purchase Price	[1]			$ 20,000
Parc at Duluth
Business Acquisition [Line Items]
Location			Duluth, GA ("Atlanta")
Structure			Triple-net Lease
Date Acquired				Jul. 31, 2015
Purchase Price				$ 52,800
Parc at Piedmont
Business Acquisition [Line Items]
Location			Marietta, GA ("Atlanta")
Structure			Triple-net Lease
Date Acquired				Jul. 31, 2015
Purchase Price				$ 50,800
The Pavilion at Great Hills
Business Acquisition [Line Items]
Location			Austin, TX
Structure			Managed
Date Acquired				Jul. 31, 2015
Purchase Price				$ 35,000
The Hampton at Meadows Place
Business Acquisition [Line Items]
Location			Meadows Place, TX ("Houston")
Structure			Managed
Date Acquired				Jul. 31, 2015
Purchase Price				$ 28,400
The Beacon at Gulf Breeze
Business Acquisition [Line Items]
Location			Gulf Breeze, FL ("Pensacola")
Structure			Managed
Date Acquired				Jul. 31, 2015
Purchase Price				$ 28,000
Palmilla Senior Living
Business Acquisition [Line Items]
Location			Albuquerque, NM
Structure			Managed
Date Acquired				Sep. 30, 2015
Purchase Price				$ 47,600
Cedar Lake Assisted Living and Memory Care
Business Acquisition [Line Items]
Location			Lake Zurich, IL ("Chicago")
Structure			Managed
Date Acquired				Sep. 30, 2015
Purchase Price				$ 30,000
The Shores of Lake Phalen
Business Acquisition [Line Items]
Location			Maplewood, MN ("St. Paul")
Structure			Managed
Date Acquired				Nov. 10, 2015
Purchase Price	[1]			$ 29,250
Park Place Senior Living at WingHaven
Business Acquisition [Line Items]
Location			O'Fallon, MO ("St. Louis")
Structure			Managed
Date Acquired				Dec. 17, 2015
Purchase Price				$ 54,000
Hearthside Senior Living of Collierville
Business Acquisition [Line Items]
Location			Collierville, TN ("Memphis")
Structure			Managed
Date Acquired				Dec. 29, 2015
Purchase Price	[1]			$ 17,000

[1] This represents a single property or portfolio acquisition that is not considered material to the Company and as such no pro forma financial information has been included related to this property.