Employee Benefits (Tables)

12 Months Ended

Dec. 31, 2017

Compensation and Retirement Disclosure [Abstract]

Schedule of Defined Benefit Plan Assumptions Used in Calculating Net Periodic Benefit Cost [Table Text Block]

Assumptions used to determine the net periodic benefit cost for the Company’s Pension Plans and postretirement benefit plan for the years ended December 31, 2017, 2016, and 2015 were as follows:



	Pension Benefits						Postretirement Benefits
	2017		2016		2015		2017		2016		2015
Weighted Average Assumptions as of December 31:
Discount Rate	4.45	%	4.70	%	4.25	%	4.57	%	4.74	%	4.28	%
Expected Long-Term Rate of Return on Plan Assets	5.75	%	6.00	%	6.00	%	—		—		—
Health Care Cost Trend Rate	—		—		—		6.50	%	6.70	%	7.00	%

Schedule of reconciliation of changes in the benefit obligation and the fair value of plan assets, as well as the funded status recognized in the consolidated statements of condition for the pension plans and postretirement benefit plan

The following table provides a reconciliation of changes in benefit obligation and fair value of plan assets, as well as the funded status recognized in the Company’s consolidated statements of condition for the Pension Plans and postretirement benefit plan for the years ended December 31, 2017 and 2016.



	Pension Benefits						Postretirement Benefits
(dollars in thousands)	2017			2016			2017			2016
Benefit Obligation at Beginning of Year	$	107,593		$	105,993		$	24,308		$	25,307
Service Cost	—			—			453			513
Interest Cost	4,665			4,882			1,093			1,134
Plan Amendment ³	—			—			(2,730		)	—
Actuarial Losses (Gains)	6,828			2,708			2,052			(1,846		)
Employer Benefits Paid ¹	(9,006		)	(5,990		)	(970		)	(800		)
Benefit Obligation at End of Year	$	110,080		$	107,593		$	24,206		$	24,308
Fair Value of Plan Assets at Beginning of Year	$	83,383		$	83,858		$	—		$	—
Actual Return on Plan Assets	12,047			5,031			—			—
Employer Contributions	10,484			484			970			800
Employer Benefits Paid ¹	(9,006		)	(5,990		)	(970		)	(800		)
Fair Value of Plan Assets at End of Year	$	96,908		$	83,383		$	—		$	—
Funded Status at End of Year ²	$	(13,172	)	$	(24,210	)	$	(24,206	)	$	(24,308	)


¹	Participants' contributions relative to the postretirement benefit plan were offset against employer benefits paid in the table above. Participants' contributions for postretirement benefits were $0.5 million and $0.8 million for the years ended December 31, 2017 and 2016, respectively.


²	Amounts are recognized in Retirement Benefits Payable in the consolidated statements of condition.

Schedule of amounts recognized in accumulated other comprehensive income (loss)

The following presents the amounts recognized in the Company’s accumulated other comprehensive income for the Pension Plans and postretirement benefit plan as of December 31, 2017 and 2016.



	Pension Benefits						Postretirement Benefits
(dollars in thousands)	2017			2016			2017		2016
Amounts Recognized in Accumulated Other Comprehensive Income (Loss), Net of Tax
Net Actuarial Gains (Losses)	$	(32,730	)	$	(33,954	)	$	3,143	$	4,647
Net Prior Service Credit	—			—			1,872		415
Total Amounts Recognized in Accumulated Other Comprehensive Income (Loss), Net of Tax	$	(32,730	)	$	(33,954	)	$	5,015	$	5,062

Schedule of components of net periodic benefit cost

Components of net periodic benefit cost for the Company’s Pension Plans and the postretirement benefit plan are presented in the following table for the years ended December 31, 2017, 2016, and 2015.



	Pension Benefits									Postretirement Benefits
(dollars in thousands)	2017			2016			2015			2017			2016			2015
Service Cost	$	—		$	—		$	—		$	453		$	513		$	621
Interest Cost	4,665			4,882			4,655			1,093			1,134			1,155
Expected Return on Plan Assets	(5,011		)	(5,121		)	(5,222		)	—			—			—
Amortization of:
Prior Service Credit¹	—			—			—			(322		)	(322		)	(322		)
Net Actuarial Losses (Gains) ¹	1,817			1,617			1,713			(435		)	(393		)	(89		)
Net Periodic Benefit Cost	$	1,471		$	1,378		$	1,146		$	789		$	932		$	1,365


¹	Represents reclassification adjustments from accumulated other comprehensive income during the period.

Schedule of assumptions used to determine the benefit obligations/net periodic cost

Assumptions used to determine the benefit obligations as of December 31, 2017 and 2016 for the Company’s Pension Plans and postretirement benefit plan were as follows:



	Pension Benefits				Postretirement Benefits
	2017		2016		2017		2016
Weighted Average Assumptions as of December 31:
Discount Rate	3.90	%	4.45	%	3.96	%	4.57	%
Health Care Cost Trend Rate Assumed For Next Year	—		—		6.30	%	6.50	%

Schedule of impact of one percent change in the health care cost trend rate assumption

A one percent change in the health care cost trend rate assumption (with all other assumptions remaining constant) would have impacted the service and interest cost components of the net periodic postretirement benefit cost and the postretirement benefit obligation as of and for the year ended December 31, 2017 as follows:



(dollars in thousands)	One Percent Increase			One Percent Decrease
Effect on the Total of Service and Interest Cost Component of Net Periodic Postretirement Benefit Cost		$	99		$	(88	)
Effect on the Postretirement Benefit Obligation		1,020			(1,022		)

Schedule of expected benefits to be paid in each of the next five years and in the aggregate for the five years thereafter

As of December 31, 2017, expected benefits to be paid in each of the next five years and in the aggregate for the five years thereafter were as follows:



(dollars in thousands)	Pension Benefits			Postretirement Benefits
2018		$	6,629		$	886
2019		6,812			926
2020		6,944			995
2021		7,070			1,074
2022		7,095			1,181
Years 2023-2027		35,416			7,619

Schedule of the fair values of the retirement plan assets by asset category



	Fair Value Measurements
Asset Category (dollars in thousands)	Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)			Significant Other Unobservable Inputs (Level 3)			Total as of Dec. 31, 2017		Total as of Dec. 31, 2016
Cash		$	2,156		$	—		$	—	$	2,156	$	1,898
Equity Securities – Mutual Funds:
Large-Cap		1,748			—			—		1,748		—
Mixed-Cap		29,459			—			—		29,459		29,593
International		24,539			—			—		24,539		18,040
Emerging Market		2,305			—			—		2,305		2,043
Fixed Income Securities – Mutual Funds		36,701			—			—		36,701		31,809
Total		$	96,908		$	—		$	—	$	96,908	$	83,383