The Davey 401KSOP and Employee Stock Ownership Plan (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Dec. 31, 2019
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Employee Stock Ownership Plan (ESOP), initial shares in ESOP	120,000
Employee Stock Ownership Plan (ESOP), shares adjusted for stock split	23,040,000
Employee Stock Ownership Plan (ESOP), initial value in ESOP	$ 2,700
Defined contribution plan, employer matching contribution, percent of employees' gross pay	2.00%
Defined contribution plan, eligible age	21 years
Defined contribution plan, service requirement for eligibility	1 year
Number of put option periods	2
Duration of put option periods	60 days
Employee Stock Ownership Plan (ESOP), fair value of shares subject to repurchase obligation	$ 2,272	$ 4,749
Company shares held in 401KSOP shares, fair value	124,443	119,806
Redeemable common shares related to 401KSOP and Employee Stock Ownership Plan (ESOP); 5,236 and 5,147 shares at redemption value as of March 28, 2020 and December 31, 2019	$ 126,715	$ 124,555
Defined Contribution Plan, Tier 1 [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay	100.00%
Defined Contribution Plan, Tier 2 [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay	50.00%
Maximum [Member] | Defined Contribution Plan, Tier 1 [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay	3.00%
Maximum [Member] | Defined Contribution Plan, Tier 2 [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay	5.00%