Multiemployer Plans (Tables)

12 Months Ended

Dec. 31, 2018

Retirement Benefits [Abstract]

Schedule of Multiemployer Plans [Table Text Block]

	EIN/Pension Plan Number	Pension Protection Act Zone Status		FIP/RP Status Pending/Implemented	Contributions						Surcharge Imposed	Expiration Date of Collective Bargaining Agreement
Pension Fund		2018	2017		2018		2017		2016
					(In thousands)
Alaska Laborers-Employers Retirement Fund	91-6028298-001	Yellow as of 6/30/2018	Yellow as of 6/30/2017	Implemented	$	732	$	690	$	766	No	12/31/2018	*
Construction Industry and Laborers Joint Pension Trust for So Nevada, Plan A	88-0135695-001	Red	Red	Implemented	346		377		523		No	6/30/2019
Edison Pension Plan	93-6061681-001	Green	Green	No	12,111		12,725		6,242		No	6/30/2019
IBEW Local 212 Pension Trust	31-6127280-001	Green as of 4/30/2018	Green as of 4/30/2017	No	1,341		1,312		1,146		No	6/2/2019
IBEW Local 357 Pension Plan A	88-6023284-001	Green	Green	No	3,460		3,286		3,016		No	5/31/2021
IBEW Local 648 Pension Plan	31-6134845-001	Yellow as of 2/28/2018	Red as of 2/28/2017	Implemented	2,175		2,254		773		No	8/29/2021
IBEW Local 82 Pension Plan	31-6127268-001	Green as of 6/30/2018	Green as of 6/30/2017	No	1,569		1,757		2,560		No	12/1/2019
Idaho Plumbers and Pipefitters Pension Plan	82-6010346-001	Green as of 5/31/2018	Green as of 5/31/2017	No	1,247		1,156		1,221		No	9/30/2019
Minnesota Teamsters Construction Division Pension Fund	41-6187751-001	Green as of 11/30/2017	Green as of 11/30/2016	No	740		826		690		No	4/30/2019
National Automatic Sprinkler Industry Pension Fund	52-6054620-001	Red	Red	Implemented	738		718		775		No	3/31/2021- 7/31/2024
National Electrical Benefit Fund	53-0181657-001	Green	Green	No	8,468		8,891		6,366		No	1/31/2018- 5/31/2022
Pension Trust Fund for Operating Engineers	94-6090764-001	Yellow	Red	Implemented	2,403		2,391		2,069		No	6/15/2019- 6/30/2020
Sheet Metal Workers Pension Plan of Southern CA, AZ, and NV	95-6052257-001	Yellow	Yellow	Implemented	1,774		1,016		1,087		No	6/30/2019
Southwest Marine Pension Trust	95-6123404-001	Red	Red	Implemented	81		48		50		No	1/31/2019	*
Other funds					21,537		19,298		17,243
Total contributions					$	58,722	$	56,745	$	44,527

* Plan includes contributions required by collective bargaining agreements which have expired, but contain provisions automatically renewing their terms in the absence of a subsequent negotiated agreement.

The Company was listed in the plans' Forms 5500 as providing more than 5 percent of the total contributions for the following plans and plan years:

Pension Fund	Year Contributions to Plan Exceeded More Than 5 Percent of Total Contributions (as of December 31 of the Plan's Year-End)
Edison Pension Plan	2017 and 2016
IBEW Local 82 Pension Plan	2017 and 2016
IBEW Local 124 Pension Trust Fund	2017 and 2016
IBEW Local 212 Pension Trust Fund	2017 and 2016
IBEW Local 357 Pension Plan A	2017 and 2016
IBEW Local 648 Pension Plan	2017 and 2016
Idaho Plumbers and Pipefitters Pension Plan	2017 and 2016
International Union of Operating Engineers Local 701 Pension Trust Fund	2017 and 2016
Minnesota Teamsters Construction Division Pension Fund	2017 and 2016
Pension and Retirement Plan of Plumbers and Pipefitters Local 525	2017 and 2016