EQUITY AND EARNINGS PER SHARE - Summary of Outstanding Options - Period End (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Date of grant of exercised options	2013-2014	[1],[2]
Date of grant of expired options	2003-2005	[1]
Stock options outstanding (in shares)	10,572,094
Exercised (in shares)	(802,492)	[2]
Expired unexercised (in shares)	(792,553)
Options Exercisable (in shares)	9,086,678
Weighted Average Exercise Price, Exercised (in dollars per share)	$ 5.81	[2],[3]
Independent Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options outstanding (in shares)	5,000
Independent Directors [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recipient	Directors
Date of Grant	Various	[1]
Stock options outstanding (in shares)	6,000
Options Exercisable (in shares)	5,000
Weighted Average Exercise Price (in dollars per share)	$ 17.54	[3]
Intrinsic Value	$ 0
2003 - 2007 [Member] | Manager [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recipient	Manager	[4]
Date of Grant	2003 - 2007	[1],[4]
Stock options outstanding (in shares)	1,226,555	[4]
Options Exercisable (in shares)	434,000	[4]
Weighted Average Exercise Price (in dollars per share)	$ 31.36	[3],[4]
Intrinsic Value	0	[4]
March 2011 [Member] | Manager [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recipient	Manager	[4]
Date of Grant	Mar-11	[1],[4]
Stock options outstanding (in shares)	838,417	[4]
Options Exercisable (in shares)	547,583	[4]
Weighted Average Exercise Price (in dollars per share)	$ 6.58	[3],[4]
Intrinsic Value	4.6	[4]
September 2011 [Member] | Manager [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recipient	Manager	[4]
Date of Grant	Sep-11	[1],[4]
Stock options outstanding (in shares)	1,269,917	[4]
Options Exercisable (in shares)	849,916	[4]
Weighted Average Exercise Price (in dollars per share)	$ 4.98	[3],[4]
Intrinsic Value	8.5	[4]
April 2012 [Member] | Manager [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recipient	Manager	[4]
Date of Grant	Apr-12	[1],[4]
Stock options outstanding (in shares)	948,750	[4]
Options Exercisable (in shares)	920,983	[4]
Weighted Average Exercise Price (in dollars per share)	$ 6.82	[3],[4]
Intrinsic Value	7.6	[4]
May 2012 [Member] | Manager [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recipient	Manager	[4]
Date of Grant	May-12	[1],[4]
Stock options outstanding (in shares)	1,150,000	[4]
Options Exercisable (in shares)	1,117,333	[4]
Weighted Average Exercise Price (in dollars per share)	$ 7.34	[3],[4]
Intrinsic Value	8.6	[4]
July 2012 [Member] | Manager [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recipient	Manager	[4]
Date of Grant	Jul-12	[1],[4]
Stock options outstanding (in shares)	1,265,000	[4]
Options Exercisable (in shares)	1,234,783	[4]
Weighted Average Exercise Price (in dollars per share)	$ 7.34	[3],[4]
Intrinsic Value	9.5	[4]
January 2013 [Member] | Manager [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recipient	Manager	[4]
Date of Grant	Jan-13	[1],[4]
Stock options outstanding (in shares)	2,875,000	[4]
Options Exercisable (in shares)	2,491,665	[4]
Weighted Average Exercise Price (in dollars per share)	$ 10.24	[3],[4]
Intrinsic Value	11.9	[4]
February 2013 [Member] | Manager [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recipient	Manager	[4]
Date of Grant	Feb-13	[1],[4]
Stock options outstanding (in shares)	1,150,000	[4]
Options Exercisable (in shares)	958,332	[4]
Weighted Average Exercise Price (in dollars per share)	$ 11.48	[3],[4]
Intrinsic Value	3.4	[4]
April 2014 [Member] | Manager [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recipient	Manager	[4]
Date of Grant	Apr-14	[1],[4]
Stock options outstanding (in shares)	1,437,500	[4]
Options Exercisable (in shares)	527,083	[4]
Weighted Average Exercise Price (in dollars per share)	$ 12.20	[3],[4]
Intrinsic Value	$ 1.5	[4]

[1] Options expire on the tenth anniversary from date of grant.

[2] Exercised by employees of Fortress, subsequent to their assignment, or by directors. The options exercised had an intrinsic value of $4.5 million.

[3] The strike prices are subject to adjustment in connection with return of capital dividends.

[4] The Manager assigned certain of its options to Fortress’s employees as follows: Date of Grant Range of StrikePrices Total UnexercisedInception to Date2004 - 2007 $29.92 to $33.80 90,5602012 $6.82 to $7.34 600,0002013 $10.24 to $11.48 1,100,4972014 $12.20 258,750Total 2,049,807