EMPLOYEE BENEFIT PLANS (Tables)

9 Months Ended

Sep. 30, 2017

Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]

Schedule of net periodic benefit cost

The components of net periodic benefit cost related to the Company’s defined benefit plans consisted of the following:

	Three Months Ended   September 30,						Nine Months Ended   September 30,
Pension Benefits	2017			2016			2017			2016
Components of net periodic benefit cost:
Service cost	$	10,142		$	10,064		$	30,429		$	24,743
Interest cost	1,084			772			3,252			2,323
Expected return on plan assets	(1,441		)	(1,234		)	(4,325		)	(3,447		)
Amortization of prior service cost	13			13			39			39
Amortization of actuarial loss (gain)	113			328			339			716
Net periodic benefit cost	$	9,911		$	9,943		$	29,734		$	24,374

	Three Months Ended   September 30,				Nine Months Ended   September 30,
Post-Retirement Medical Plan	2017		2016		2017		2016
Components of net periodic benefit cost:
Service cost	$	316	$	304	$	948	$	743
Interest cost	172		131		516		398
Amortization of prior service cost	162		161		484		379
Amortization of actuarial loss (gain)	—		—		—		—
Net periodic benefit cost	$	650	$	596	$	1,948	$	1,520