EMPLOYEE BENEFIT PLANS (Tables)

12 Months Ended

Dec. 31, 2017

Compensation and Retirement Disclosure [Abstract]

Schedule of components of pension expense, the funded status of the plan, amounts recognized in the consolidated statements of financial condition, and major assumptions

(Dollars in Thousands)	2017		2016		2015
Change in Projected Benefit Obligation:
Benefit Obligation at Beginning of Year	$	152,585	$	141,039	$	140,359
Service Cost		6,752		6,453		6,859
Interest Cost		5,750		5,587		5,750
Actuarial Loss (Gain)		10,877		9,118		(6,880)
Benefits Paid		(10,541)		(9,412)		(4,825)
Expenses Paid		(339)		(200)		(224)
Projected Benefit Obligation at End of Year	$	165,084	$	152,585	$	141,039
Change in Plan Assets:
Fair Value of Plan Assets at Beginning of Year	$	113,813	$	105,792	$	108,172
Actual Return on Plan Assets		16,786		7,633		(2,331)
Employer Contributions		10,000		10,000		5,000
Benefits Paid		(10,541)		(9,412)		(4,825)
Expenses Paid		(339)		(200)		(224)
Fair Value of Plan Assets at End of Year	$	129,719	$	113,813	$	105,792
Funded Status of Plan and Accrued Liability Recognized at End of Year:
Other Liabilities	$	35,365	$	38,772	$	35,247
Accumulated Benefit Obligation at End of Year	$	144,139	$	130,109	$	121,609
Components of Net Periodic Benefit Costs:
Service Cost	$	6,752	$	6,453	$	6,859
Interest Cost		5,750		5,587		5,750
Expected Return on Plan Assets		(8,026)		(7,736)		(7,820)
Amortization of Prior Service Costs		223		278		309
Net Loss Amortization		3,812		3,201		3,564
Net Periodic Benefit Cost	$	8,511	$	7,783	$	8,662
Weighted-Average Assumptions Used to Determine Benefit Obligation:
Discount Rate		3.71%		4.21%		4.52%
Rate of Compensation Increase		3.25%		3.25%		3.25%
Measurement Date		12/31/17		12/31/16		12/31/15
Weighted-Average Assumptions Used to Determine Benefit Cost:
Discount Rate		4.21%		4.52%		4.15%
Expected Return on Plan Assets		7.25%		7.50%		7.50%
Rate of Compensation Increase		3.25%		3.25%		3.25%
Amortization Amounts from Accumulated Other Comprehensive Income:
Net Actuarial Loss	$	2,117	$	9,221	$	3,272
Prior Service Cost		(223)		(278)		(309)
Net Loss		(3,812)		(3,201)		(3,564)
Deferred Tax (Benefit) Expense		5,898		(2,216)		232
Other Comprehensive Loss (Gain), net of tax	$	3,980	$	3,526	$	(369)
Amounts Recognized in Accumulated Other Comprehensive Income:
Net Actuarial Losses	$	38,698	$	40,392	$	34,373
Prior Service Cost		265		488		766
Deferred Tax Benefit		(9,876)		(15,772)		(13,556)
Accumulated Other Comprehensive Loss, net of tax	$	29,087	$	25,108	$	21,583

Schedule of pension plan asset allocation and the target asset allocation

	Target		Percentage of Plan
	Allocation		Assets at Year-End(1)
	2018		2017		2016
Equity Securities	70	%	74	%	66	%
Debt Securities	25	%	21	%	20	%
Cash and Cash Equivalents	5	%	5	%	14	%
Total	100	%	100	%	100	%

Schedule of fair value of plan assets by level of the valuation inputs within the fair value hierarchy

(Dollars in Thousands)	2017		2016
Level 1:
Mutual Funds	$	118,474	$	96,079
Cash and Cash Equivalents		7,103		15,345
Level 2:
U.S. Government Agency		4,142		2,389
Total Fair Value of Plan Assets	$	129,719	$	113,813

Schedule of expected benefit payments related to the defined benefit pension plan

Expected Benefit Payments. As of December 31, expected benefit payments related to the defined benefit pension plan were as follows:
(Dollars in Thousands)	2017
2018	$	11,487
2019		11,471
2020		10,563
2021		12,488
2022		10,936
2023 through 2027		57,441
Total	$	114,386

Schedule of amounts contributed to the pension plan and the expected amount to be contributed

					Expected
					Contribution
(Dollars in Thousands)		2016		2017	2018(1)
Actual Contributions	$	10,000	$	10,000	$	10,000

Schedule of components of SERP's periodic benefit cost, the funded status of the plan, amounts recognized in the consolidated statements of financial condition, and major assumptions

(Dollars in Thousands)	2017		2016		2015
Change in Projected Benefit Obligation:
Benefit Obligation at Beginning of Year	$	5,741	$	4,842	$	3,003
Service Cost		-		-		3
Interest Cost		191		162		133
Actuarial Loss		1,353		737		1,703
Projected Benefit Obligation at End of Year	$	7,285	$	5,741	$	4,842
Funded Status of Plan and Accrued Liability Recognized at End of Year:
Other Liabilities	$	7,285	$	5,741	$	4,842
Accumulated Benefit Obligation at End of Year	$	6,485	$	4,913	$	4,348
Components of Net Periodic Benefit Costs:
Service Cost	$	-	$	-	$	3
Interest Cost		191		162		133
Amortization of Prior Service Cost		-		-		7
Net Loss Amortization		597		759		179
Net Periodic Benefit Cost	$	788	$	921	$	322
Weighted-Average Assumptions Used to Determine Benefit Obligation:
Discount Rate		3.53%		3.92%		4.13%
Rate of Compensation Increase		3.25%		3.25%		3.25%
Measurement Date		12/31/17		12/31/16		12/31/15
Weighted-Average Assumptions Used to Determine Benefit Cost:
Discount Rate		3.92%		4.13%		4.15%
Rate of Compensation Increase		3.25%		3.25%		3.25%
Amortization Amounts from Accumulated Other Comprehensive Income:
Net Actuarial Loss	$	1,353	$	737	$	1,703
Prior Service Cost		-		-		(7)
Net Loss		(597)		(759)		(179)
Deferred Tax (Benefit) Expense		(77)		8		(585)
Other Comprehensive Loss (Gain), net of tax	$	679	$	(14)	$	932
Amounts Recognized in Accumulated Other Comprehensive Income:
Net Actuarial Loss	$	1,626	$	870	$	892
Deferred Tax Benefit		(412)		(336)		(344)
Accumulated Other Comprehensive Loss, net of tax	$	1,214	$	534	$	548

Schedule of expected benefit payments related to the SERP

(Dollars in Thousands)	2017
2018	$	3,427
2019		3,995
2020		-
2021		-
2022		-
2023 through 2027		-
Total	$	7,422