PREFERRED STOCK - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended			12 Months Ended
	Sep. 15, 2015	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Preferred stock, authorized (in shares)		1,000,000			1,000,000	1,000,000
Preferred stock, issued (in shares)		726,500			726,500	770,000
Preferred stock, outstanding (in shares)		726,500			726,500	770,000
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
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
Dividends paid on mandatory convertible preferred stock					$ 39,414	$ 10,106	$ 0
Increase to retained earnings on repurchase of mandatory convertible preferred stock					$ 11,285	$ 0	$ 0
Depositary shares repurchased during period (in shares)		105,000	265,000	65,000	435,000
Depository shares equivalent to preferred stock units (in shares)		43,500			43,500
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
Preferred Stock
Class of Stock [Line Items]
Issuance of preferred stock (in dollars per share)	$ 100.00