STOCKHOLDERS' EQUITY - Capital Stock (Details) - USD ($) $ in Thousands	1 Months Ended			6 Months Ended	12 Months Ended
	Jul. 24, 2015	Jun. 30, 2015	Jan. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Issuance of common stock, shares		1,051,664	3,750,202
Proceeds for the issuance of common stock		$ 66,900	$ 285,400	$ 352,167	$ 242,107
Sales agent commissions for common stock sales		1,000	$ 4,400
Common stock reserved for future issuance, amount (up to $1.0 Billion)		$ 1,000,000		1,000,000
Common Stock
Business Acquisition [Line Items]
Proceeds for the issuance of common stock				$ 1,201	$ 845
American Realty Capital Healthcare Trust | Common Stock
Business Acquisition [Line Items]
Business acquisition, equity interest issued, number of shares			28,400,000
American Realty Capital Healthcare Trust | Limited Partnership Units
Business Acquisition [Line Items]
Business acquisition, equity interest issued, number of shares			1,100,000
Subsequent Event
Business Acquisition [Line Items]
Issuance of common stock, shares	579,652
Proceeds for the issuance of common stock	$ 36,400
Sales agent commissions for common stock sales	$ 600