LONG-TERM DEBT (Details)		3 Months Ended		6 Months Ended
	Aug. 01, 2014 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	May 07, 2013 USD ($)
Debt
Available for sale securities		$ 38,087,000		$ 38,087,000		$ 0
Senior secured term loan		482,626,000		482,626,000		536,598,000
Less: debt issuance costs, net		(5,071,000)		(5,071,000)		(6,184,000)
Less: unamortized discount, net		(1,834,000)		(1,834,000)		(2,236,000)
Net long-term debt		475,721,000		475,721,000		528,178,000
Less: current portion		(5,945,000)		(5,945,000)		(5,945,000)
Long-term debt, less current portion		469,776,000		469,776,000		522,233,000
Extinguishment of debt, amount		$ 51,000,000	$ 16,000,000
Percentage discount of par received on early extinguishment of debt		13.20%	9.00%
Gains (losses) on extinguishment of debt		$ 5,464,000	$ 1,114,000	5,464,000	$ 1,114,000
Interest on long-term debt		5,988,000	7,195,000	12,529,000	14,355,000
Senior secured term loan
Debt
Less: debt issuance costs, net		$ (5,100,000)		(5,100,000)		(6,200,000)
Debt instrument accordion feature increase in additional borrowings							$ 200,000,000.0
Aggregate amount of each consecutive quarterly scheduled principal installment	$ 1,486,000
Mandatory prepayments owed				$ 0
Interest rate at the end of the period (as a percent)		4.50%		4.50%
Accumulated amortization		$ 5,200,000		$ 5,200,000		$ 4,100,000
Interest on long-term debt		$ 6,000,000	$ 7,200,000	$ 12,500,000	$ 14,400,000
Senior secured term loan | Maximum
Debt
Leverage ratio to be maintained under the credit facility covenants				3.0
Covenant threshold, leverage ratio				3.50
Number of days within which the entity fails to pay principal when due or interest or any other amount owing on any other obligation under the credit agreement, is considered as event of default				5 days
Amount of principal or interest if failed to pay considered as event of default				$ 40,000,000
Amount of debt which results in acceleration of debt if failed to pay considered as event of default				40,000,000
Amount of unbonded, undischarged or unstayed debt under entry by court of one or more judgments for certain period to determine as event of default				$ 40,000,000
Senior secured term loan | Minimum
Debt
Leverage ratio to be maintained under the credit facility covenants				1.00
Covenant threshold, leverage ratio				1.00
Senior secured term loan | Adjusted Eurodollar Rate
Debt
Reference rate				Adjusted Eurodollar Rate
Fixed interest rate base (as a percent)				1.00%
Interest rate margin (as a percent)				3.50%
Senior secured term loan | Base Rate
Debt
Reference rate				Base Rate
Fixed interest rate base (as a percent)				2.00%
Interest rate margin (as a percent)				2.50%