EMPLOYEE BENEFIT PLANS (Tables)

9 Months Ended

Sep. 30, 2018

Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]

Components of the Net Periodic Benefit Cost

Components of the net periodic benefit cost of PLC’s defined benefit pension plan for the three and nine months ended September 30, 2018 and 2017, are as follows: 

	For The Three Months Ended September 30,										For The Nine Months Ended September 30,
	2018					2017					2018					2017
	Qualified Pension Plan			Nonqualified Excess Pension Plan		Qualified Pension Plan			Nonqualified Excess Pension Plan		Qualified Pension Plan			Nonqualified Excess Pension Plan		Qualified Pension Plan			Nonqualified Excess Pension Plan
	(Dollars In Thousands)
Service cost — benefits earned during the period	$	3,006		$	288	$	3,348		$	334	$	9,888		$	1,062	$	10,044		$	1,002
Interest cost on projected benefit obligation	2,577			359		2,191			297		7,371			1,077		6,573			891
Expected return on plan assets	(4,743		)	—		(3,352		)	—		(12,795		)	—		(10,056		)	—
Amortization of prior service cost	—			—		—			—		—			—		—			—
Amortization of actuarial loss/(gain)	—			196		—			118		—			726		—			354
Preliminary net periodic benefit cost	840			843		2,187			749		4,464			2,865		6,561			2,247
Settlement/curtailment expense(1)	—			986		—			—		—			986		—			—
Total net periodic benefit costs	$	840		$	1,829	$	2,187		$	749	$	4,464		$	3,851	$	6,561		$	2,247
(1) The unfunded excess benefit plan triggered settlement accounting for the nine months ended September 30, 2018 since total lump sum payments exceeded the settlement threshold of service cost plus interest cost.