PREFERRED STOCK - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	Sep. 15, 2015	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Class of Stock [Line Items]
Preferred stock, authorized (in shares)		1,000,000		1,000,000		1,000,000
Preferred stock, issued (in shares)		737,000		737,000		770,000
Gain on repurchase of mandatory convertible preferred stock		$ 6,467		$ 7,747
Depositary shares repurchased during period (in shares)		265,000	65,000	330,000
Depository shares equivalent to preferred stock units (in shares)		33,000		33,000
Depositary shares (in shares)	7,700,000
Preferred stock, dividend rate	5.25%
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01		$ 0.01		$ 0.01
Issuance of preferred stock (in dollars per share)	$ 100.00
Gross proceeds from issuance of preferred stock	$ 770,000
Preferred stock, liquidation preference (in dollars per share)	$ 1,000
Depositary Shares, Liquidation Preference Per Share	$ 100.00
Payments of preferred stock		$ 9,700		$ 29,853	$ 0
Minimum
Class of Stock [Line Items]
Common stock issuable upon conversion (in shares)	5.8716
Maximum
Class of Stock [Line Items]
Common stock issuable upon conversion (in shares)	7.3394