EMPLOYEE BENEFIT PLANS (Details 2) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		8 Months Ended	9 Months Ended	12 Months Ended
	Jan. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Defined Benefit Pension Plan
EMPLOYEE BENEFIT PLANS
Service cost - benefits earned during the period		$ 2,973		$ 7,928
Interest cost on projected benefit obligation		2,433		6,488
Expected return on plan assets		(3,642)		(9,712)
Total net periodic benefit cost		1,764		4,704
Unfunded Excess Benefits Plan
EMPLOYEE BENEFIT PLANS
Service cost - benefits earned during the period		333		888
Interest cost on projected benefit obligation		408		1,088
Total net periodic benefit cost		$ 741		1,976
PLC | Defined Benefit Pension Plan
EMPLOYEE BENEFIT PLANS
Contribution made by the company to its defined benefit pension plan				$ 1,400
Adjusted funding target percentage to be maintained, minimum				80.00%
Predecessor | Defined Benefit Pension Plan
EMPLOYEE BENEFIT PLANS
Service cost - benefits earned during the period	$ 974		$ 2,227		$ 6,680	$ 9,411
Interest cost on projected benefit obligation	1,002		2,587		7,761	10,493
Expected return on plan assets	(1,293)		(3,065)		(9,194)
Amortization of prior service cost	(33)		(98)		(294)
Amortization of actuarial losses	668		1,576		4,727
Total net periodic benefit cost	1,318		3,227		9,680
Contribution made by the company to its defined benefit pension plan	$ 2,165					15,513
Weighted-average assumptions used to determine benefit obligations
Discount rate (as a percent)	3.55%
Predecessor | Unfunded Excess Benefits Plan
EMPLOYEE BENEFIT PLANS
Service cost - benefits earned during the period	$ 95		226		678	954
Interest cost on projected benefit obligation	140		406		1,219	1,696
Amortization of prior service cost	1		3		9
Amortization of actuarial losses	138		321		962
Total net periodic benefit cost	374		$ 956		$ 2,868
Contribution made by the company to its defined benefit pension plan	$ 122					$ 1,907
Weighted-average assumptions used to determine benefit obligations
Discount rate (as a percent)	3.26%
Predecessor | Group life insurance plan
Weighted-average assumptions used to determine benefit obligations
Discount rate (as a percent)	3.79%
Predecessor | PLC | Defined Benefit Pension Plan
EMPLOYEE BENEFIT PLANS
Contribution made by the company to its defined benefit pension plan	$ 2,200