Employee Benefit Plans - Summary of Plan Information Relating to Participation in Multiemployer Pension Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Multiemployer Plans [Line Items]
Contributions	$ 134,197	$ 126,191	$ 110,082
National Electrical Benefit Fund
Multiemployer Plans [Line Items]
Contributions	44,414	35,399	29,161
Central Pension Fund of the IUOE & Participating Employers
Multiemployer Plans [Line Items]
Contributions	11,638	9,246	12,176
Pipeline Industry Pension Fund
Multiemployer Plans [Line Items]
Contributions	9,376	10,132	13,585
Excavators Union Local 731 Pension Fund
Multiemployer Plans [Line Items]
Contributions	6,697	0	0
Eighth District Electrical Pension Fund
Multiemployer Plans [Line Items]
Contributions	5,939	3,332	3,208
Operating Engineers Local 324 Pension Fund
Multiemployer Plans [Line Items]
Contributions	4,315	2,310	1,969
Local 697 IBEW and Electrical Industry Pension Fund
Multiemployer Plans [Line Items]
Contributions	3,717	2,656	1,127
Teamsters National Pipe Line Pension Plan
Multiemployer Plans [Line Items]
Contributions	3,039	3,318	3,602
Laborers Pension Trust Fund for Northern California
Multiemployer Plans [Line Items]
Contributions	2,823	3,652	3,387
Locals 302 & 612 of the IUOE-Employers Construction Industry Retirement Plan
Multiemployer Plans [Line Items]
Contributions	2,392	2,620	2,194
Laborers National Pension Fund
Multiemployer Plans [Line Items]
Contributions	1,910	2,051	3,049
West Virginia Laborers Pension Trust Fund
Multiemployer Plans [Line Items]
Contributions	1,693	3,321	509
International Union of Operating Engineers Local 132 Pension Fund
Multiemployer Plans [Line Items]
Contributions	1,289	3,367	222
Michigan Laborers’ Pension Plan
Multiemployer Plans [Line Items]
Contributions	1,491	1,061	0
Plumbers and Pipefitters National Pension Fund
Multiemployer Plans [Line Items]
Contributions	1,162	2,734	1,273
OE Pension Trust Fund
Multiemployer Plans [Line Items]
Contributions	956	1,922	1,703
Employer-Teamsters Local Nos 175 & 505 Pension Trust Fund
Multiemployer Plans [Line Items]
Contributions	530	1,209	50
Laborers District Council of W PA Pension Fund
Multiemployer Plans [Line Items]
Contributions	1,194	1,029	418
Alaska Electrical Pension Plan
Multiemployer Plans [Line Items]
Contributions	66	2,287	2,143
All other plans - U.S.
Multiemployer Plans [Line Items]
Contributions	23,105	26,027	21,029
All other plans - Canada
Multiemployer Plans [Line Items]
Contributions	$ 6,451	$ 8,518	$ 9,277