EQUITY (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Mar. 02, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
STOCKHOLDERS' EQUITY AND MEMBERS' CAPITAL
AOG Units (in shares)		212,356,696	211,243,045
Direct Ownership Interest		100.00%	100.00%
Dividend rate, percentage		7.00%
Redemption price (dollars per unit)		$ 25.00
Stock issuance costs	$ 0.7
Preferred Equity
STOCKHOLDERS' EQUITY AND MEMBERS' CAPITAL
Partners' capital (in units)		12,400,000	12,400,000
Ares Owners Holdings, L.P.
STOCKHOLDERS' EQUITY AND MEMBERS' CAPITAL
AOG Units (in shares)		117,576,663	117,928,313
Direct Ownership Interest		55.36%	55.82%
For the Year Ended December 31,		55.52%	56.07%	56.27%
Alleghany
STOCKHOLDERS' EQUITY AND MEMBERS' CAPITAL
AOG Units (in shares)		12,500,000	12,500,000
Direct Ownership Interest		5.89%	5.92%
For the Year Ended December 31,		5.89%	5.89%	5.87%
Abu Dhabi Investment Authority and Affiliates
STOCKHOLDERS' EQUITY AND MEMBERS' CAPITAL
Number of shares issued in transaction (in shares)	7,500,000
Ares Operating Group
STOCKHOLDERS' EQUITY AND MEMBERS' CAPITAL
AOG Units (in shares)		82,280,033	80,814,732
Direct Ownership Interest		38.75%	38.26%
For the Year Ended December 31,		38.59%	38.04%	37.86%