Textuals (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Employee Benefit Plans [Line Items]
Defined Benefit Plan, Service Cost	$ 4,602	$ 5,242	$ 4,328
Defined contribution plan, employer discretionary contribution amount		20,600	10,000
Defined contribution plan, cost recognized	27,100	42,000	31,300
Deferred Compensation Liability, Classified, Noncurrent	$ 25,200	$ 21,900
Defined Benefit Plan, Description	The Company sponsors a contributory defined benefit plan (the "Plan") covering substantially all Canadian employees of EECOL. The Plan provides retirement benefits based on earnings and credited service, and participants contribute 2% of their earnings to the Plan. Participants become 100% vested after two years of continuous service or, if earlier, at the participant's normal retirement age.
Defined Benefit Plan, Unfunded Plan	The Company also sponsors a Supplemental Executive Retirement Plan (the "SERP"), which provides additional pension benefits to certain executives of EECOL based on earnings, and credited service. Effective January 1, 2013, the SERP was closed to new participants and existing participants became 100% vested. SERP participants continue to contribute 4% of their earnings to the Plan.
Pension Plan [Member]
Schedule of Employee Benefit Plans [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.20%	4.00%
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	$ 3,200
Other Nonoperating Gains (Losses)	$ (1,400)	$ (1,900)	$ (1,800)
Supplemental Employee Retirement Plan [Member]
Schedule of Employee Benefit Plans [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.20%	4.00%
Other Postretirement Benefits Plan [Member]
Schedule of Employee Benefit Plans [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	$ 400
United States
Schedule of Employee Benefit Plans [Line Items]
Defined contribution plan, employer matching contribution, percent	50.00%
Defined contribution plan, maximum annual contribution per employee, percent	6.00%
Canada | Minimum
Schedule of Employee Benefit Plans [Line Items]
Defined contribution plan, employer matching contribution, percent	3.00%
Canada | Maximum
Schedule of Employee Benefit Plans [Line Items]
Defined contribution plan, employer matching contribution, percent	5.00%