Retirement Plans (Tables)

12 Months Ended

Dec. 31, 2018

Retirement Benefits [Abstract]

Summary of Changes in Plan Assets and Plan Benefit Obligations

The following table summarizes the changes in plan assets and plan benefit obligations:

Year Ended December 31,	2018			2017
(Dollars in thousands)
Change in benefit obligation
Beginning benefit obligation	$	29,759		$	27,612
Interest cost		1,086			1,189
Actuarial (gain) loss		(2,486	)		2,300
Benefit payments		(1,406	)		(1,342	)
Ending benefit obligation	$	26,953		$	29,759

Summary of Defined Benefit Plans

Year Ended December 31,	2018			2017
(Dollars in thousands)
Change in plan assets
Fair value of plan assets at beginning of year	$	—		$	—
Employer contribution		1,406			1,342
Benefit payments		(1,406	)		(1,342	)
Fair value of plan assets at end of year	$	—		$	—
Funded status	$	(26,953	)	$	(29,759	)
Amounts recognized in the consolidated balance sheets consist of:
Accrued expenses		(1,392	)		(1,407	)
Other non-current liabilities		(25,561	)		(28,352	)
Net amount recognized	$	(26,953	)	$	(29,759	)
Amounts recognized in accumulated other comprehensive loss consist of:
Net actuarial loss	$	4,799		$	7,722
Prior service cost		(1	)		(1	)
Net amount recognized, before tax effect	$	4,798		$	7,721
Weighted average assumptions used to determine benefit obligations:
Discount rate		4.4	%		3.7	%
Rate of compensation increase		3.0	%		3.0	%

Summary of Components of Net Periodic Pension Cost

Components of net periodic pension cost are described in the following table:

Year Ended December 31,	2018			2017			2016
(Dollars in thousands)
Components of net periodic pension cost:
Interest cost		1,086			1,189			1,216
Amortization of actuarial loss		438			369			335
Net periodic pension cost		1,524			1,558		$	1,551
Weighted average assumptions used to determine net periodic pension cost:
Discount rate		3.7	%		4.4	%		4.4	%
Rate of compensation increase		3.0	%		3.0	%		3.0	%

Summary of Expected Benefit Payments

Benefit payments during the next ten years, which reflect applicable future service, are as follows:

Year Ended December 31,	Amount
(Dollars in thousands)
2019	$	1,422
2020	$	1,484
2021	$	1,457
2022	$	1,495
2023	$	1,472
Years 2024 to 2028	$	8,448

Periodic Pension Cost, Next Fiscal Year

The following is an estimate of the components of net periodic pension cost in 2019:

Estimated Year Ended December 31,	2019
(Dollars in thousands)
Interest cost		1,144
Amortization of actuarial loss		209
Estimated 2019 net periodic pension cost	$	1,353