Defined Benefit Pension Plans (Tables)

12 Months Ended

Dec. 31, 2016

Compensation and Retirement Disclosure [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,
	2016			2015
Change in benefit obligation
Projected benefit obligation at beginning of year	$	27,228		$	35,876
Service cost	370			35
Interest cost	1,243			1,486
Actuarial (gains)/losses	1,150			(2,445		)
New longevity assumptions	(447		)	(340		)
Amendments	341			—
Curtailments	—			(404		)
Settlements	(4,873		)	(6,186		)
Benefits paid	(179		)	(794		)
Projected benefit obligation at end of year	$	24,833		$	27,228
Accumulated benefit obligation at end of year	$	24,833		$	27,228

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

	December 31,
	2016			2015
Change in fair value of plan assets
Fair value of plan assets at beginning of year	$	15,216		$	21,567
Actual return on plan assets	400			(135		)
Plan expenses, including PBGC premiums	(727		)	(536		)
Employer contributions	1,672			1,300
Settlements	(4,873		)	(6,186		)
Benefits paid	(179		)	(794		)
Fair value of plan assets at end of year	$	11,509		$	15,216

Schedule of net funded status [Table Text Block]

	December 31,
	2016			2015
Funded status of the plans
Fair value of plan assets	$	11,509		$	15,216
Projected benefit obligation	24,833			27,228
Funded status of the plans	$	(13,324	)	$	(12,012	)

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

	December 31,
	2016			2015
Amounts reported in the consolidated balance sheets
Current liability	$	(83	)	$	(499	)
Noncurrent liability	(13,241		)	(11,513		)
Funded status of the plans	$	(13,324	)	$	(12,012	)

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, 2016				At December 31, 2015
	Pretax		Net of Tax		Pretax		Net of Tax
Amounts reported in accumulated other comprehensive income
Unrecognized net actuarial loss	$	10,675	$	6,456	$	11,836	$	7,150
Unrecognized prior service cost	341		206		—		—
	$	11,016	$	6,662	$	11,836	$	7,150

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

The total amortization associated with these amounts that is expected to be recognized in net periodic benefit expense for 2017 follows: 

	Year ending December 31, 2017
	Pretax		Net of Tax
Amortization of Costs Expected to be Recognized Next Year
Unrecognized net actuarial loss	$	949	$	569
Unrecognized prior service cost	64		38
	$	1,013	$	607

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,
	2016		2015
For pension plans with accumulated benefit obligations in excess of plan assets
Projected benefit obligation	$	24,833	$	27,228
Accumulated benefit obligation	24,833		27,228
Fair value of plan assets	11,509		15,216

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,
	2016		2015		2014
Actuarial assumptions
Discount rate	4.20	%	4.70	%	4.30	%
Expected long-term rate of return on plan assets	5.00		7.25		7.50

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,
	2016			2015			2014
Components of pension expense (income)
Service costs--increase in benefit obligation earned	$	370		$	35		$	51
Interest cost on projected benefit obligation	1,243			1,486			1,618
Expected return on plan assets	(1,044		)	(1,576		)	(1,993		)
Curtailment loss	—			49			—
Settlement loss	2,346			2,915			2,065
Amortization of net actuarial loss	951			1,400			708
Amortization of prior service cost	—			6			14
Net pension expense of defined benefit pension plans	$	3,866		$	4,315		$	2,463

Schedule of allocation of plan assets [Table Text Block]

The fair values of our pension plan assets at December 31, 2016 by asset category, using the three-level hierarchy of fair value inputs, were as follows:  

			Fair Value Measurements at December 31, 2016 Using:
Description	Total Carrying Value at December 31, 2016		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Asset Category
Money market funds	$	2,882	$	—	$	2,882	$	—
U.S. large-cap equities
Growth	687		687		—		—
Value	729		729		—		—
U.S. small/mid-cap equities
Growth	339		339		—		—
Value	339		339		—		—
International equities
Growth	443		443		—		—
Value	514		514		—		—
Fixed income	4,669		4,669		—		—
Multiclass world-allocation mutual funds	907		907		—		—
	$	11,509	$	8,627	$	2,882	$	—

The fair values of our pension plan assets at December 31, 2015 by asset category, using the three-level hierarchy of fair value inputs, were as follows:

			Fair Value Measurements at December 31, 2015 Using:
Description	Total Carrying Value at December 31, 2015		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Asset Category
Money market funds	$	2,794	$	—	$	2,794	$	—
U.S. large-cap equities
Growth	1,869		1,869		—		—
Value	1,492		1,492		—		—
U.S. small/mid-cap equities
Growth	781		781		—		—
Value	1,003		1,003		—		—
International equities
Growth	1,270		1,270		—		—
Value	1,183		1,183		—		—
Fixed income	3,035		3,035		—		—
Multiclass world-allocation mutual funds	1,789		1,789		—		—
	$	15,216	$	12,422	$	2,794	$	—

Schedule of expected benefit payments [Table Text Block]

The benefits, as of December 31, 2016, 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, follow:

	Participants Benefits
Estimated future payments
Year ending December 31, 2017	$	659
2018	878
2019	981
2020	1,088
2021	1,167
Years 2022 to 2026	6,677

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.

P. Defined Benefit Pension Plans (continued)

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
		2016	2015		2016		2015		2014
National Electric Benefit Fund	53-0181657/001	Green	Green	No	$	712	$	774	$	743	No	Ranging from June 30, 2017 to December 31, 2018
Eighth District Electrical Pension Fund	84-6100393/001	Green	Green	No	90		119		105		No	December 31, 2017
					$	802	$	893	$	848