COMPONENTS OF PENSION PLAN NET PERIODIC BENEFIT COSTS (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Oct. 16, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Pension Plan
Components of net periodic benefit cost:
Service cost			$ 524		$ 1,720
Interest cost		$ 1,138	1,118	$ 3,408	3,381
Expected return on plan assets		(1,240)	(1,363)	(3,743)	(3,937)
Amortization of prior service cost (1)		46		140
Amortization of net loss		774	787	2,319	2,365
Net periodic benefit cost		$ 718	$ 1,066	2,124	$ 3,529
2016 plan year
Components of net periodic benefit cost:
Employer contribution				1,100
2017 plan year
Components of net periodic benefit cost:
Employer contribution	$ 600			$ 1,200