Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2018

Retirement Benefits [Abstract]

Schedule of Changes in Projected Benefit Obligations [Table Text Block]

A December 31 measurement date is used for all of the defined benefit and postretirement plans. The status of these plans as of December 31, 2018 and 2017 is summarized below (dollars in thousands):

	December 31,
	Pension Benefits						Other Benefits
	2018			2017			2018			2017
Change in benefit obligation:
Benefit obligation at beginning of year	$	172,143		$	161,955		$	70,198		$	60,524
Service cost	12,502			10,686			3,028			2,543
Interest Cost	5,405			5,326			2,319			2,118
Participant contributions	—			—			432			354
Amendments	—			159			—			—
Actuarial (gains) losses	(1,045		)	11,336			(7,172		)	5,510
Settlement (gains) losses	—			(438		)	—			—
Settlements	—			(12,907		)	—			—
Benefits paid	(7,801		)	(5,974		)	(1,409		)	(851		)
Foreign exchange translations and other adjustments	(2,600		)	2,000			—			—
Benefit obligation at end of year	$	178,604		$	172,143		$	67,396		$	70,198

Schedule of Changes in Fair Value of Plan Assets [Table Text Block]

	December 31,
	Pension Benefits						Other Benefits
	2018			2017			2018			2017
Change in plan assets:
Fair value of plan assets at beginning of year	$	103,236		$	84,770		$	—		$	—
Actual return on plan assets	(6,464		)	14,481			—			—
Employer contributions	13,590			22,866			977			497
Participant contributions	—			—			432			354
Disbursement for settlements	—			(12,907		)	—			—
Benefits paid and expenses	(7,801		)	(5,974		)	(1,409		)	(851		)
Fair value of plan assets at end of year	$	102,561		$	103,236		$	—		$	—
Funded status at end of year	$	(76,043	)	$	(68,907	)	$	(67,396	)	$	(70,198	)

Schedule of Net Funded Status [Table Text Block]

	December 31,
	Qualified Plans						Non-Qualified Plans(1)						Total
	2018			2017			2018			2017			2018			2017
Aggregate fair value of plan assets	$	102,561		$	103,236		$	—		$	—		$	102,561		$	103,236
Aggregate projected benefit obligations	112,093			107,072			66,511			65,071			178,604			172,143
Under funded	$	(9,532	)	$	(3,836	)	$	(66,511	)	$	(65,071	)	$	(76,043	)	$	(68,907	)

(1) For non-qualified plans, there are no required funding levels.

Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]

	December 31,
	Pension Benefits				Other Benefits
	2018		2017		2018			2017
Amounts recognized in accumulated other comprehensive income:
Net actuarial loss	$	48,744	$	40,058	$	25,923		$	35,672
Net prior service cost (credit)	436		804		(10,491		)	(11,806		)
Total	$	49,180	$	40,862	$	15,432		$	23,866

Schedule Of Projected Benefit Obligations In Excess Of Fair Value Of Plan Assets [Table Text Block]

The following table presents information for qualified and non-qualified pension plans with a projected benefit obligation in excess of plan assets as of December 31, 2018 and 2017 (dollars in thousands):

	2018		2017
Projected benefit obligation	$	178,604	$	172,143
Fair value of plan assets	102,561		103,236

Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block]

The following table presents information for pension plans with an accumulated benefit obligation in excess of plan assets as of December 31, 2018 and 2017 (dollars in thousands):

	2018		2017
Accumulated benefit obligation	$	174,400	$	169,705
Fair value of plan assets	102,561		103,236

Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]

The components of net periodic benefit cost, included in other operating expenses on the consolidated statements of income, and other changes in plan assets and benefit obligations recognized in other comprehensive income were as follows (dollars in thousands):

	Pension Benefits									Other Benefits
	2018			2017			2016			2018			2017			2016
Net periodic benefit cost:
Service cost	$	12,502		$	10,686		$	10,319		$	3,028		$	2,543		$	2,883
Interest cost	5,405			5,326			4,790			2,319			2,118			2,259
Expected return on plan assets	(7,535		)	(6,215		)	(5,138		)	—			—			—
Amortization of net actuarial losses	3,728			4,382			4,323			2,577			1,992			1,827
Amortization of prior service cost (credit)	344			344			294			(1,315		)	(1,315		)	(622		)
Settlements	—			4,785			1,026			—			—			—
Net periodic benefit cost	14,444			19,308			15,614			6,609			5,338			6,347
Other changes in plan assets and benefit obligations recognized in other comprehensive income:
Net actuarial (gains) losses	12,954			2,633			8,785			(7,172		)	5,507			6,228
Amortization of net actuarial (losses)	(3,728		)	(4,382		)	(4,323		)	(2,577		)	(1,992		)	(1,827		)
Amortization of prior service (cost) credit	(344		)	(344		)	(294		)	1,315			1,315			622
Settlements	—			(4,785		)	(1,026		)	—			—			—
Prior service cost (credit)	—			159			—			—			—			(13,743		)
Foreign exchange translations and other adjustments	(565		)	759			707			—			—			—
Total recognized in other comprehensive income	8,317			(5,960		)	3,849			(8,434		)	4,830			(8,720		)
Total recognized in net periodic benefit cost and other comprehensive income	$	22,761		$	13,348		$	19,463		$	(1,825	)	$	10,168		$	(2,373	)

Schedule of Expected Benefit Payments [Table Text Block]

The following benefit payments, which reflect expected future service as appropriate, are expected to be paid (dollars in thousands):

	Pension Benefits		Other Benefits
2019	$	9,977	$	1,528
2020	12,013		1,835
2021	11,663		2,209
2022	14,229		2,633
2023	14,128		3,009
2024-2028	77,832		20,359

Schedule of Assumptions Used [Table Text Block]

Weighted average assumptions used to determine the accumulated benefit obligation and net benefit cost or income were as follows:

	Pension Benefits						Other Benefits
	2018		2017		2016		2018		2017		2016
Discount rate used to determine benefit obligation	4.02	%	3.40	%	3.80	%	4.17	%	3.56	%	4.10	%
Discount rate used to determine net benefit cost or income	3.41	%	3.81	%	3.95	%	3.56	%	4.10	%	4.43	%
Expected long-term rate of return on plan assets	7.35	%	7.35	%	7.35	%	—	%	—	%	—	%
Rate of compensation increases	4.17	%	4.16	%	4.08	%	—	%	—	%	—	%

Schedule of Health Care Cost Trend Rates [Table Text Block]

The assumed health care cost trend rates used in measuring the accumulated non-pension post-retirement benefit obligation were as follows:

	December 31,
	2018	2017
Pre-Medicare eligible claims	8% down to 5% in 2024	9% down to 5% in 2024
Medicare eligible claims	8% down to 5% in 2024	9% down to 5% in 2024

Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block]

The assumed health care cost trend rates used in measuring the accumulated non-pension post-retirement benefit obligation were as follows:

	December 31,
	2018	2017
Pre-Medicare eligible claims	8% down to 5% in 2024	9% down to 5% in 2024
Medicare eligible claims	8% down to 5% in 2024	9% down to 5% in 2024

Schedule of Allocation of Plan Assets [Table Text Block]

The fair values of the Company’s qualified pension plan assets as of December 31, 2018 and 2017 are summarized below (dollars in thousands):

	December 31, 2018
			Fair Value Measurement Using:
	Total		Level 1		Level 2		Level 3
Mutual Funds(1)	$	102,414	$	102,414	$	—	$	—
Cash	147		147		—		—
Total	$	102,561	$	102,561	$	—	$	—

(1) Mutual funds were invested 25% in U.S. equity funds, 42% in U.S. fixed income funds, 17% in non-U.S. equity funds and 16% in other.

	December 31, 2017
			Fair Value Measurement Using:
	Total		Level 1		Level 2		Level 3
Mutual Funds(2)	$	103,106	$	103,106	$	—	$	—
Cash	130		130		—		—
Total	$	103,236	$	103,236	$	—	$	—

(2) Mutual funds were invested 27% in U.S. equity funds, 36% in U.S. fixed income funds, 22% in non-U.S. equity funds and 15% in other.