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Employee Benefit Plans - Summary of Multi-Employer Benefit Plans (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | $ 121,850 | $ 102,209 | $ 70,420
All other plans |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | 17,663 | 17,117 | 8,818
Southern California IBEW-NECA Pension Trust Fund | Multiemployer Plans, Pension |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | 32,791 | 14,268 | 767
National Electrical Benefit Fund | Multiemployer Plans, Pension |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | 10,850 | 11,050 | 9,840
Eighth District Electrical Pension Fund | Multiemployer Plans, Pension |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | 10,998 | 11,199 | 9,707
IBEW Local 332 Pension Plan Part A | Multiemployer Plans, Pension |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | 3,418 | 1,913 | 0
IBEW Local 769 Management Pension Plan A | Multiemployer Plans, Pension |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | 3,866 | 2,689 | 2,587
IBEW Local No. 640 and Arizona NECA Defined Benefit Pension Plan | Multiemployer Plans, Pension |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | 1,195 | 2,397 | 1,629
IBEW Local Union 1249 Pension Fund | Multiemployer Plans, Pension |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | 2,126 | 1,578 | 881
Indiana/Kentucky/Ohio Regional Council of Carpenters Pension Fund | Multiemployer Plans, Pension |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | 2,109 | 1,742 | 1,157
Alaska Electrical Pension Plan | Multiemployer Plans, Pension |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | 1,548 | 1,408 | 2,723
National Electrical Annuity Plan | Other Postretirement Benefits Plan |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | 25,037 | 28,822 | 26,559
Eighth District Electrical Pension Fund Annuity Plan | Other Postretirement Benefits Plan |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | 4,915 | 5,339 | 4,785
San Mateo Country Electrical Construction Industry Retirement Plan | Other Postretirement Benefits Plan |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | 3,202 | 854 | 0
Puget Sound Electrical Workers 401(K) Savings Plan | Other Postretirement Benefits Plan |  |  |
Multiemployer Plan, Employer Contribution, Cost [Abstract] |  |  |
Contributions to Plan | $ 2,132 | $ 1,833 | $ 967

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- Definition Amount of cost for employer contribution to multiemployer plan. Multiemployer plan includes, but is not limited to, pension plan determined to be individually significant and insignificant and other postretirement benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=35742348&loc=SL14450788-114948 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 35 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=29639808&loc=d3e29008-114946 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 9 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450691-114947 + Details
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