Defined Benefit Pension Plans (Tables)

12 Months Ended

Dec. 31, 2018

Retirement Benefits [Abstract]

Schedule of changes in projected benefit obligations [Table Text Block]

The change in benefit obligations and the fair value of plans assets follows:

	December 31,
	2018			2017
Change in benefit obligation
Projected benefit obligation at beginning of year	$	19,403		$	24,833
Service cost	400			530
Interest cost	718			1,002
Actuarial (gains)/losses	(77		)	1,865
Amendments	—			—
Settlements	(13,118		)	(8,400		)
Benefits paid	(262		)	(427		)
Projected benefit obligation at end of year	$	7,064		$	19,403
Accumulated benefit obligation at end of year	$	7,064		$	19,403

Schedule of changes in fair value of plan sssets [Table Text Block]

	December 31,
	2018			2017
Change in fair value of plan assets
Fair value of plan assets at beginning of year	$	7,105		$	11,509
Actual return on plan assets	239			845
Plan expenses, including PBGC premiums	(364		)	(513		)
Employer contributions	10,158			4,091
Settlements	(13,118		)	(8,400		)
Benefits paid	(262		)	(427		)
Fair value of plan assets at end of year	$	3,758		$	7,105

Schedule of net funded status [Table Text Block]

	December 31,
	2018			2017
Funded status of the plans
Fair value of plan assets	$	3,758		$	7,105
Projected benefit obligation	7,064			19,403
Funded status of the plans	$	(3,306	)	$	(12,298	)
	December 31,
	2018			2017
Funded status by plan
ERP	$	(332	)	$	(9,084	)
SERP	(2,564		)	(2,759		)
Restoration Plan	(410		)	(455		)
	$	(3,306	)	$	(12,298	)

Schedule of amounts recognized in balance sheet [Table Text Block]

	December 31,
	2018			2017
Amounts reported in the consolidated balance sheets
Current liability	$	(187	)	$	(175	)
Noncurrent liability	(3,119		)	(12,123		)
Funded status of the plans	$	(3,306	)	$	(12,298	)

Schedule of amounts in accumulated other comprehensive income [Table Text Block]

Amounts included in accumulated other comprehensive income (loss), related to our defined benefit pension plans follow:

	At December 31, 2018					At December 31, 2017
	Pretax		Net of Tax			Pretax		Net of Tax
Amounts reported in accumulated other comprehensive income
Unrecognized net actuarial loss	$	2,139	$	(714	)	$	8,086	$	4,919
Unrecognized prior service cost	214		(71		)	278		169
	$	2,353	$	(785	)	$	8,364	$	5,088

Schedule of amounts in accumulated other comprehensive income (loss) to be recognized over next fiscal year [Table Text Block]

P.    Defined Benefit Pension Plans (continued)

The total amortization associated with these amounts that is expected to be recognized in net periodic benefit expense for 2019 follows: 

	Year ending December 31, 2019
	Pretax		Net of Tax
Amortization of Costs Expected to be Recognized Next Year
Unrecognized net actuarial loss	$	175	$	131
Unrecognized prior service cost	64		48
	$	239	$	179

Schedule of accumulated benefit obligations in excess of fair value of plan assets [Table Text Block]

The aggregate projected benefit obligation, accumulated benefit obligation and fair value of plan assets for plans in which the fair value of plan assets is less than either the projected benefit obligation or accumulated benefit obligation follow:

	December 31,
	2018		2017
For pension plans with accumulated benefit obligations in excess of plan assets
Projected benefit obligation	$	7,064	$	19,403
Accumulated benefit obligation	7,064		19,403
Fair value of plan assets	3,758		7,105

Schedule of assumptions used [Table Text Block]

The actuarial assumptions follow. The discount rates were used to measure the year-end benefit obligation and compute pension expense for the subsequent year.

	December 31,
	2018		2017		2016
Actuarial assumptions
Discount rate	4.35	%	3.70	%	4.20	%
Expected long-term rate of return on plan assets	2.50		2.50		5.00

Components of pension expense (income) [Table Text Block]

Net periodic benefit expense (income) associated with the defined benefit pension plans included the following components:

	Year Ended December 31,
	2018			2017			2016
Components of pension expense (income)
Service costs--increase in benefit obligation earned	$	400		$	530		$	370
Interest cost on projected benefit obligation	718			1,002			1,243
Expected return on plan assets	(231		)	(638		)	(1,044		)
Curtailment loss	—			—			—
Settlement loss	5,499			3,849			2,346
Amortization of net actuarial loss	728			909			951
Amortization of prior service cost	64			64			—
Net pension expense of defined benefit pension plans	$	7,178		$	5,716		$	3,866

Schedule of allocation of plan assets [Table Text Block]

The fair values of our pension plan assets at December 31, 2018 by asset category, using the three-level hierarchy of fair value inputs, were as follows:

			Fair Value Measurements at December 31, 2018 Using:
Description	Total Carrying Value at December 31, 2018		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Asset Category
Money market funds	$	3,758			$	3,758	$	—
U.S. large-cap equities
Growth	—				—		—
Value	—				—		—
U.S. small/mid-cap equities
Growth	—				—		—
Value	—				—		—
International equities
Growth	—				—		—
Value	—				—		—
Fixed income	—				—		—
Multiclass world-allocation mutual funds	—				—		—
	$	3,758	$	—	$	3,758	$	—

P. Defined Benefit Pension Plans (continued)

The fair values of our pension plan assets at December 31, 2017 by asset category, using the three-level hierarchy of fair value inputs, were as follows:

			Fair Value Measurements at December 31, 2017 Using:
Description	Total Carrying Value at December 31, 2017		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Asset Category
Money market funds	$	897	$	—	$	897	$	—
U.S. large-cap equities
Growth	576		576		—		—
Value	542		542		—		—
U.S. small/mid-cap equities
Growth	246		246		—		—
Value	247		247		—		—
International equities
Growth	376		376		—		—
Value	366		366		—		—
Fixed income	3,070		3,070		—		—
Multiclass world-allocation mutual funds	785		785		—		—
	$	7,105	$	6,208	$	897	$	—

Schedule of expected benefit payments [Table Text Block]

The benefits, as of December 31, 2018, expected to be paid to defined-benefit plan participants in each of the next five years, and in the aggregate for the five years thereafter, follows:

	Participants Benefits
Estimated future payments
Year ending December 31, 2019	$	356
2020	379
2021	384
2022	386
2023	389
Years 2024 to 2028	1,986

Schedule of multiemployer plans [Table Text Block]

Our participation in the multiemployer defined benefit pension plans is summarized in the table below. The “EIN/Pension Plan Number” column provides the Employer Identification Number (“EIN”) and the three-digit plan number. The most recent Pension Protection Act of 2006 (the “PPA”) zone status is from the Form 5500, “Annual Return/Report of Employee Benefit Plan,” filed by the plan and certified by the plan's actuary. The PPA zone status describes plans that are underfunded. Among other factors, plans in the “critical” red zone are generally less than 65% funded; plans in the “endangered” yellow zone are less than 80% funded; and, plans in the “safe” green zone are at least 80% funded.

Pension Fund	EIN/Pension Plan Number	Pension Protection Act Zone Status		FIP/RP Status Pending Implemented	Davey Tree Contributions						Surcharge Imposed	Expiration Dates of Bargaining Agreement
		2018	2017		2018		2017		2016
National Electric Benefit Fund	53-0181657/001	Green	Green	No	$	768	$	785	$	712	No	Ranging from December 31, 2018 to December 31, 2022
Eighth District Electrical Pension Fund	84-6100393/001	Green	Green	No	142		102		90		No	December 26, 2020
					$	910	$	887	$	802