COMPONENTS OF PENSION PLAN NET PERIODIC BENEFIT COSTS (Details) - USD ($) $ in Thousands			3 Months Ended		6 Months Ended		12 Months Ended
		Jul. 15, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Pension Plan
Components of net periodic benefit cost:
Service cost			$ 619	$ 544	$ 1,237	$ 1,087
Interest cost			1,074	1,018	2,148	2,037
Expected return on plan assets			(1,394)	(1,337)	(2,795)	(2,738)
Amortization of net actuarial gain	[1]		835	162	1,677	387
Net periodic benefit cost			$ 1,134	$ 387	2,267	$ 773
Expected contribution for pension plan in 2015							$ 3,100
2014 plan year
Components of net periodic benefit cost:
Employer contribution					600
2015 plan year
Components of net periodic benefit cost:
Employer contribution		$ 700			$ 700

[1] Amortization of net actuarial gain is included in the operating expenses line item within our condensed consolidated statements of income.