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Multiemployer Plans Participation by Plan (Details 19) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 30-1133956 |  |
Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Multiemployer Plan, Pension, Insignificant, Employer Contribution, Cost | $ 30,931 | $ 24,512 | $ 21,421
Multiemployer Plan, Employer Contribution, Cost | $ 85,444 | $ 72,525 | 58,722
Alaska Laborers-Employers Retirement Fund | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 91-6028298 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Yellow | Yellow |
Multiemployer Plan, Pension, Significant, Certified Zone Status, Date | Jun. 30, 2020 | Jun. 30, 2019 |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | Implemented |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 828 | $ 815 | 732
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Dec. 31, 2020 |  |
Construction Industry and Laborers Joint Pension Trust for So Nevada, Plan A | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 88-0135695 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Red | Red |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | Implemented |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 515 | $ 544 | 346
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Jun. 30, 2023 |  |
Edison Pension Plan | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 93-6061681 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Green | Green |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 16,121 | $ 12,252 | 12,111
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Dec. 31, 2021 |  |
IBEW Local 212 Pension Trust | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 31-6127280 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Green | Green |
Multiemployer Plan, Pension, Significant, Certified Zone Status, Date | Apr. 30, 2020 | Apr. 30, 2019 |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 1,521 | $ 1,110 | 1,341
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Jun. 01, 2025 |  |
IBEW Local 357 Pension Plan A | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 88-6023284 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Green | Green |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 9,913 | $ 10,162 | 3,460
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | May 31, 2021 |  |
IBEW Local 38 Pension Plan | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 34-6574238 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Red | Yellow |
Multiemployer Plan, Pension, Significant, Certified Zone Status, Date | Apr. 30, 2020 | Apr. 30, 2019 |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | Implemented |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 140 | $ 158 | 116
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Apr. 23, 2023 |  |
IBEW Local 648 Pension Plan | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 31-6134845 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Yellow | Yellow |
Multiemployer Plan, Pension, Significant, Certified Zone Status, Date | Feb. 28, 2020 | Feb. 28, 2019 |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | Implemented |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 526 | $ 728 | 2,175
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Aug. 29, 2021 |  |
IBEW Local 82 Pension Plan | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 31-6127268 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Green | Green |
Multiemployer Plan, Pension, Significant, Certified Zone Status, Date | Jun. 30, 2020 | Jun. 30, 2019 |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 1,373 | $ 1,662 | 1,569
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Dec. 03, 2023 |  |
Idaho Plumbers and Pipefitters Pension Plan | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 82-6010346 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Green | Green |
Multiemployer Plan, Pension, Significant, Certified Zone Status, Date | May 31, 2020 | May 31, 2019 |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 1,370 | $ 1,307 | 1,247
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Mar. 31, 2023 |  |
Minnesota Teamsters Construction Division Pension Fund | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 41-6187751 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Green | Green |
Multiemployer Plan, Pension, Significant, Certified Zone Status, Date | Nov. 30, 2019 | Nov. 30, 2018 |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 663 | $ 673 | 740
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Apr. 30, 2021 |  |
National Automatic Sprinkler Industry Pension Fund | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 52-6054620 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Red | Red |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | Implemented |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 954 | $ 1,074 | 738
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
National Automatic Sprinkler Industry Pension Fund | Pension Benefits | Minimum |  |  |
Multiemployer Plans [Line Items] |  |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Mar. 31, 2021 |  |
National Automatic Sprinkler Industry Pension Fund | Pension Benefits | Maximum |  |  |
Multiemployer Plans [Line Items] |  |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Jul. 31, 2024 |  |
National Electrical Benefit Fund | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 53-0181657 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Green | Green |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 14,484 | $ 12,679 | 8,468
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
National Electrical Benefit Fund | Pension Benefits | Minimum |  |  |
Multiemployer Plans [Line Items] |  |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Dec. 31, 2021 |  |
National Electrical Benefit Fund | Pension Benefits | Maximum |  |  |
Multiemployer Plans [Line Items] |  |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Aug. 30, 2025 |  |
Pension Trust Fund for Operating Engineers | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 94-6090764 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Yellow | Yellow |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | Implemented |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 2,680 | $ 2,598 | 2,403
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
Pension Trust Fund for Operating Engineers | Pension Benefits | Minimum |  |  |
Multiemployer Plans [Line Items] |  |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Jun. 15, 2022 |  |
Pension Trust Fund for Operating Engineers | Pension Benefits | Maximum |  |  |
Multiemployer Plans [Line Items] |  |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Jun. 30, 2023 |  |
Sheet Metal Workers Pension Plan of Southern CA, AZ, and NV | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 95-6052257 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Yellow | Yellow |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | Implemented |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 3,255 | $ 2,119 | 1,774
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Jun. 30, 2024 |  |
Southwest Marine Pension Trust | Pension Benefits |  |  |
Multiemployer Plans [Line Items] |  |  |
Entity tax ID number | 95-6123404 |  |
Multiemployer Plan, Pension, Significant, Plan Number | 001 |  |
Multiemployer Plan, Pension, Significant, Certified Zone Status [Fixed List] | Red | Red |
Multiemployer Plan, Pension, Significant, Funding Improvement or Rehabilitation Plan, Implementation Status [Fixed List] | Implemented |  |
Multiemployer Plan, Pension, Significant, Employer Contribution, Cost | $ 170 | $ 132 | $ 81
Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] | No |  |
Multiemployer Plan, Pension, Significant, Collective-Bargaining Arrangement, Expiration Date | Jan. 31, 2024 |  |

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