ACQUISITIONS (Details)	3 Months Ended			3 Months Ended						12 Months Ended	3 Months Ended		12 Months Ended			1 Months Ended	3 Months Ended				1 Months Ended	12 Months Ended			1 Months Ended			1 Months Ended		12 Months Ended		1 Months Ended
	Mar. 31, 2015 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2014 USD ($)	Mar. 31, 2015 Triple-Net Leased Properties USD ($)	Mar. 31, 2014 Triple-Net Leased Properties USD ($)	Mar. 31, 2015 Senior Living Operations USD ($)	Mar. 31, 2014 Senior Living Operations USD ($)	Mar. 31, 2015 MOB Operations USD ($)	Mar. 31, 2014 MOB Operations USD ($)	Dec. 31, 2014 Other Acquisitions USD ($)	Mar. 31, 2015 Other Acquisitions Triple-Net Leased Properties USD ($)	Mar. 31, 2015 Other Acquisitions Seniors Housing Communities And Hospitals [Member] Triple-Net Leased Properties property	Dec. 31, 2014 Other Acquisitions Seniors Housing Communities Triple-Net Leased Properties property	Dec. 31, 2014 Other Acquisitions Seniors Housing Communities Senior Living Operations property	Dec. 31, 2014 Other Acquisitions Private Hospitals Triple-Net Leased Properties property	Feb. 13, 2015 Other Acquisitions Skilled Nursing Facilities Triple-Net Leased Properties property	Mar. 31, 2015 2015 Acquisitions USD ($)	Mar. 31, 2014 2015 Acquisitions USD ($)	Mar. 31, 2015 2015 Acquisitions Senior Living Operations USD ($)	Mar. 31, 2015 2015 Acquisitions MOB Operations USD ($)	Jan. 31, 2015 American Realty Capital Healthcare Trust USD ($) property	Dec. 31, 2014 2014 Acquisitions USD ($)	Dec. 31, 2014 2014 Acquisitions Triple-Net Leased Properties USD ($)	Dec. 31, 2014 2014 Acquisitions Senior Living Operations USD ($)	Aug. 31, 2014 Holiday Retirement CAD	Aug. 31, 2004 Holiday Retirement CAD	Jul. 31, 2014 Holiday Retirement Unsecured Term Loan Unsecured Term Loan Due 2015 CAD	Aug. 31, 2014 Holiday Retirement Seniors Housing Communities property	Dec. 31, 2014 2014 Development Projects USD ($)	Dec. 31, 2014 2014 Development Projects Seniors Housing Communities property	Dec. 31, 2014 2014 Development Projects Medical Office Buildings property	Jan. 31, 2015 Common Stock Par Value American Realty Capital Healthcare Trust	Jan. 31, 2015 Limited Partnership Units American Realty Capital Healthcare Trust
Business Acquisition [Line Items]
Number of real estate properties acquired												5	26	4	3	12					152							29
Business combination, consideration transferred, stock conversion ratio, per acquiree share																					0.1688
Business combination, consideration transferred, price per acquiree share																					$ 11.33
Business acquisition, equity interest issued, number of shares										148,241																						28,400,000	1,100,000
Total cash used																	$ 1,072,538,000				$ 11,000,000	$ 1,468,724,000	$ 599,782,000	$ 868,942,000
Assumed debt																	177,857,000		77,940,000	99,917,000	167,000,000	241,077,000	12,927,000	228,150,000		193,700,000
Repayments of debt																					730,000,000
Business combination, consideration transferred										812,000,000	320,000,000														957,000,000
Early debt repayment costs										18,800,000															26,900,000
Debt instrument, face amount																											791,000,000
Number of real estate properties completed																														1	2
Total net real estate property	21,418,659,000		18,985,559,000																										41,200,000
Revenues	884,024,000	741,470,000		267,342,000	238,994,000	446,914,000	371,061,000	145,848,000	119,875,000								65,700,000
NOI																	39,700,000
Business acquisition, transaction costs																	33,500,000
Merger-related expenses and deal costs	$ 35,172,000	$ 10,760,000															$ 22,800,000	$ 0