Acquisitions and Disposition - 2015 Acquisitions (Details) $ in Thousands																																													1 Months Ended	12 Months Ended
	Dec. 30, 2015 USD ($)	Dec. 29, 2015 USD ($)	Dec. 22, 2015 USD ($)	Dec. 21, 2015 USD ($)	Dec. 18, 2015 USD ($)	Dec. 17, 2015 USD ($) ft² shares	Dec. 01, 2015 USD ($)	Nov. 13, 2015 USD ($)	Nov. 02, 2015 USD ($) ft²	Oct. 30, 2015 USD ($)	Oct. 19, 2015 USD ($)	Oct. 16, 2015 USD ($) ft²	Oct. 13, 2015 USD ($)	Sep. 30, 2015 USD ($)	Sep. 09, 2015 USD ($) shares	Sep. 04, 2015 USD ($) buildings	Sep. 01, 2015 USD ($)	Aug. 31, 2015 USD ($)	Aug. 21, 2015 USD ($) ft²	Aug. 19, 2015 USD ($)	Aug. 14, 2015 USD ($)	Jul. 31, 2015 USD ($)	Jul. 24, 2015 USD ($)	Jul. 17, 2015 USD ($)	Jun. 30, 2015 USD ($)	Jun. 26, 2015 USD ($)	Jun. 05, 2015 USD ($) shares	Jun. 01, 2015 USD ($)	May. 29, 2015 USD ($)	May. 28, 2015 USD ($)	Apr. 30, 2015 USD ($)	Apr. 15, 2015 USD ($)	Apr. 10, 2015 USD ($)	Mar. 31, 2015 USD ($)	Mar. 27, 2015 USD ($)	Feb. 27, 2015 USD ($)	Feb. 17, 2015 USD ($)	Feb. 13, 2015 USD ($)	Feb. 05, 2015 USD ($) properties shares	Jan. 29, 2015 USD ($)	Jan. 28, 2015 USD ($) shares	Jan. 23, 2015 USD ($)	Jan. 22, 2015 USD ($)	Jul. 24, 2013 properties	Feb. 17, 2015 properties	Dec. 31, 2015 USD ($) states healthcareproperty buildings shares	Dec. 31, 2014 USD ($) properties states shares	Dec. 31, 2013 USD ($) shares
Business Acquisition [Line Items]
Number of operating healthcare properties																																														66	61
Number of states in which operating healthcare properties and land parcel located | states																																														22	15
Aggregate purchase price																																														$ 818,600
Loan investments																																														22,400
Acquisition price																																														840,958	$ 543,436
Number of medical office buildings | properties																																												19
Acquisition costs capitalized																																														400	1,700
Acquisition expenses																																														14,893	10,897	$ 1,938
Revenue of acquired since acquisition																																														41,400
Income of acquiree since acquisition																																														$ 10,600
Edina MOB
Business Acquisition [Line Items]
Acquisition price																																											$ 14,190
Crystal MOB
Business Acquisition [Line Items]
Acquisition price																																											14,782
Savage MOB
Business Acquisition [Line Items]
Acquisition price																																											12,800
Dell Road MOB
Business Acquisition [Line Items]
Acquisition price																																											$ 6,410
Vadnais Heights MOB
Business Acquisition [Line Items]
Acquisition price																																								$ 18,422
Minnetonka MOB
Business Acquisition [Line Items]
Acquisition price																																							$ 26,000
Number of units issued for funding purchase price (in shares) | shares																																							44,685
Jamestown MOB
Business Acquisition [Line Items]
Acquisition price																																							$ 12,819
Minnesota Eye MOB
Business Acquisition [Line Items]
Acquisition price																																					$ 10,882
Columbus MOB
Business Acquisition [Line Items]
Acquisition price																																										$ 6,540
Methodist Sports MOB
Business Acquisition [Line Items]
Acquisition price																																									$ 10,000
Indianapolis South (4 MOBs)
Business Acquisition [Line Items]
Acquisition price																																						$ 17,183
Number of medical office buildings | buildings																																														4
Baylor Cancer Center
Business Acquisition [Line Items]
Acquisition price																																				$ 8,200
Bridgeport Medical Center
Business Acquisition [Line Items]
Acquisition price																																				$ 13,750
Renaissance Office Building
Business Acquisition [Line Items]
Acquisition price																																			$ 6,500
University of Rochester Strong Memorial Portfolio (5 MOBs)
Business Acquisition [Line Items]
Acquisition price																																		$ 41,000
Number of medical office buildings | buildings																																														5
Avalon Park Florida Hospital MOB
Business Acquisition [Line Items]
Acquisition price																																		$ 14,600
Premier Surgery Center of Louisville
Business Acquisition [Line Items]
Acquisition price																																	$ 8,000
Baton Rouge MOB
Business Acquisition [Line Items]
Acquisition price																																$ 10,486
Healthpark Medical Center
Business Acquisition [Line Items]
Acquisition price																															$ 18,913
Plaza HCA MOB
Business Acquisition [Line Items]
Acquisition price																															$ 19,000
Northern Ohio Medical Center
Business Acquisition [Line Items]
Acquisition price																														$ 11,236
University of Michigan - Northville MOB
Business Acquisition [Line Items]
Acquisition price																													$ 14,750
Coon Rapids Medical Center MOB
Business Acquisition [Line Items]
Acquisition price																												$ 7,298
Mezzanine Loan - UF Health MOB
Business Acquisition [Line Items]
Acquisition price																												9,000
Mezzanine Loan - UF Health MOB | Mezzanine loan
Business Acquisition [Line Items]
Mezzanine term loan																												$ 9,000
Mortgage loan interest rate																												8.40%
Premier Landmark MOB
Business Acquisition [Line Items]
Acquisition price																											$ 11,308
Palm Beach ASC
Business Acquisition [Line Items]
Acquisition price																										$ 14,070
Brookstone Physician Center MOB
Business Acquisition [Line Items]
Acquisition price																									$ 2,800
Jackson Woman's Clinic MOB
Business Acquisition [Line Items]
Acquisition price																									5,672
Hillside Medical Center MOB
Business Acquisition [Line Items]
Acquisition price																									11,400
Randall Road MOB
Business Acquisition [Line Items]
Acquisition price																									$ 13,045
Randall Road MOB - Unit 140
Business Acquisition [Line Items]
Acquisition price																								$ 1,750
Medical Specialists of Palm Beach MOB
Business Acquisition [Line Items]
Acquisition price																							$ 11,051
OhioHealth - SW Health Center MOB
Business Acquisition [Line Items]
Acquisition price																						$ 11,460
Trios Health MOB
Business Acquisition [Line Items]
Acquisition price																						$ 64,000
IMS - Paradise Valley MOB
Business Acquisition [Line Items]
Acquisition price																					$ 31,814
IMS - Avondale MOB
Business Acquisition [Line Items]
Acquisition price																				$ 22,144
IMS - Palm Valley MOB
Business Acquisition [Line Items]
Acquisition price																				$ 35,184
IMS - North Mountain MOB
Business Acquisition [Line Items]
Acquisition price																		$ 51,740
Mezzanine Loan - Warm Springs Rehab Hospital
Business Acquisition [Line Items]
Acquisition price																			$ 3,138
Mezzanine Loan - Warm Springs Rehab Hospital | Mezzanine loan
Business Acquisition [Line Items]
Mezzanine term loan																			$ 3,100
Mortgage loan interest rate																			8.50%
Memorial Hermann Medical Complex (2 MOBs)
Business Acquisition [Line Items]
Acquisition price																	$ 40,400
Number of medical office buildings | buildings																																														2
Construction Loan - Tinseltown
Business Acquisition [Line Items]
Acquisition price																$ 1,005
Number of medical office buildings | buildings																2
Mezzanine term loan																$ 1,000
Mortgage loan interest rate																9.00%
New Albany Medical Center MOB
Business Acquisition [Line Items]
Acquisition price															$ 11,200
Fountain Hills Medical Campus MOB
Business Acquisition [Line Items]
Acquisition price														$ 13,250
Catalyst Portfolio (12 MOBs)
Business Acquisition [Line Items]
Acquisition price													$ 23,805
Number of medical office buildings | buildings																																														12
Mezzanine Loan - Truman Medical Center
Business Acquisition [Line Items]
Acquisition price												$ 4,500
Area of property (in square feet) | ft²												87,500
Mezzanine term loan												$ 4,500
Mortgage loan interest rate												8.02%
Arete Surgical Center
Business Acquisition [Line Items]
Acquisition price											$ 9,100
Cambridge Professional Center MOB
Business Acquisition [Line Items]
Acquisition price										$ 11,550
Mezzanine Loan - Great Falls Replacement Surgical Hospital
Business Acquisition [Line Items]
Acquisition price									$ 4,500
Area of property (in square feet) | ft²									63,250
Mezzanine Loan - Great Falls Replacement Surgical Hospital | Mezzanine loan
Business Acquisition [Line Items]
Mezzanine term loan									$ 4,500
Mortgage loan interest rate									9.00%
HonorHealth 44th Street MOB
Business Acquisition [Line Items]
Acquisition price								$ 7,163
Mercy Medical Center MOB
Business Acquisition [Line Items]
Acquisition price							$ 9,850
Nashville MOB
Business Acquisition [Line Items]
Acquisition price						$ 45,440
Number of units issued for funding purchase price (in shares) | shares						91,236
Mezzanine Loan - Wilson Surgery Center
Business Acquisition [Line Items]
Acquisition price						$ 216
Area of property (in square feet) | ft²						9,890
Mezzanine Loan - Wilson Surgery Center | Mezzanine loan
Business Acquisition [Line Items]
Mezzanine term loan						$ 200
Mortgage loan interest rate						8.80%
Hillside Medical Center - Suite 100
Business Acquisition [Line Items]
Acquisition price					$ 4,240
Randall Road MOB - Suite 170
Business Acquisition [Line Items]
Acquisition price				$ 408
KSF Orthopaedic MOB
Business Acquisition [Line Items]
Acquisition price			$ 6,250
Great Falls Clinic MOB
Business Acquisition [Line Items]
Acquisition price		$ 24,244
Percentage of interest acquired		75.00%
Randall Road MOB - Suite 320
Business Acquisition [Line Items]
Acquisition price	$ 500
Operating Partnership | Units
Business Acquisition [Line Items]
Acquisition price																																														$ 32,500	$ 103,600	$ 37,500
Number of units issued for funding purchase price (in shares) | shares																																														648,649	2,042,313	954,877
Value of units issued for funding purchase price																																														$ 11,000	$ 28,600	$ 11,500
Operating Partnership | Minnesota Portfolio
Business Acquisition [Line Items]
Number of medical office buildings | properties																																							1						7
Ownership percentage by noncontrolling owners																																							1.00%
Operating Partnership | Minnetonka MOB | Series A Preferred units | Units
Business Acquisition [Line Items]
Number of units issued for funding purchase price (in shares) | shares																																							44,685
Acquisition expenses																																							$ 9,700
Operating Partnership | Methodist Sports MOB | Units
Business Acquisition [Line Items]
Number of units issued for funding purchase price (in shares) | shares																																									420,963
Value of units issued for funding purchase price																																									$ 7,300
Operating Partnership | Premier Landmark MOB | Units
Business Acquisition [Line Items]
Number of units issued for funding purchase price (in shares) | shares																											210,820
Value of units issued for funding purchase price																											$ 3,400
Operating Partnership | Mezzanine Loan - Warm Springs Rehab Hospital
Business Acquisition [Line Items]
Area of property (in square feet) | ft²																			54,500
Operating Partnership | New Albany Medical Center MOB | Units
Business Acquisition [Line Items]
Number of units issued for funding purchase price (in shares) | shares															16,866
Value of units issued for funding purchase price															$ 200
Operating Partnership | Nashville MOB | Series A Preferred units | Units
Business Acquisition [Line Items]
Number of units issued for funding purchase price (in shares) | shares						91,236
Value of units issued for funding purchase price						$ 19,700