Employee Benefit Plans	6 Months Ended
Jun. 30, 2022
Retirement Benefits [Abstract]
Employee Benefit Plans	Note 14. Employee Benefit Plans Multiemployer pension plans Certain Company subsidiaries, including certain subsidiaries in Canada, contribute amounts to multiemployer pension plans and other multiemployer benefit plans and trusts, which are recorded as a component of employee wages and salaries within costs of revenues. Contributions are generally based on fixed amounts per hour per employee for employees covered under these plans. Multiemployer plan contribution rates are determined annually and assessed on a pay-as-you-go basis based on union employee payrolls. Union payrolls cannot be determined for future periods because the number of union employees employed at a given time, and the plans in which they participate, vary depending upon the location and number of ongoing projects and the need for union resources in connection with those projects. Total consolidated contributions to multiemployer plans were $27 and $24 during the three months ended June 30, 2022 and 2021, respectively, and $51 and $43 during the six months ended June 30, 2022 and 2021, respectively. Defined benefit pension plans The Company assumed both funded and unfunded foreign defined benefit pension plans that cover a portion of the Company's employees, and the largest plans are closed to new participants. Refer to Note 15 - "Pension" for more information on these plans. Profit sharing plans The Company has a trustee-administered profit sharing retirement plan covering substantially all of the Company's employees in the U.S. not covered by collective bargaining agreements and also adopted a profit sharing plan for employees in Canada (collectively, “Profit Sharing Plans”). The Profit Sharing Plans provide for annual discretionary contributions in amounts based on a performance grid as determined by the Company’s directors. In connection with these plans, the Company recognized $4 in expense during both the three months ended June 30, 2022 and 2021, and $6 and $7 in expense during the six months ended June 30, 2022 and 2021, respectively. Employee stock purchase plan Most of the Company’s employees in the U.S. and Canada, including named executive officers, are eligible to participate in the Company’s Employee Stock Purchase Plan (the “ESPP”). Sales of shares of the Company’s common stock under the ESPP are generally made pursuant to offerings that are intended to satisfy the requirements of Section 423 of the Internal Revenue Code. The ESPP permits employees of the Company to purchase common stock at a price equal to 85% of the lesser of (i) the market value of the common stock on the first day of the offering period, or (ii) the market value of the common stock on the purchase date, whichever is lower. Participants are subject to eligibility requirements and may not purchase more than 500 shares in any offering period or more than ten thousand dollars of common stock in a year under the ESPP. The Company recognized $1 of expense during both the three months ended June 30, 2022 and 2021, and $2 of expense during both the six months ended June 30, 2022 and 2021. Post-retirement benefit plans As part of the Chubb Acquisition, the Company assumed an unfunded post-retirement benefit plan that provides life benefits to certain eligible retirees in Canada. As of June 30, 2022, the benefit obligation was $4. The PBO discount rate was 3.0% at June 30, 2022. Benefit payments, including amounts to be paid from corporate assets, and reflecting expected future service, as appropriate, are expected to be less than $1 for 2023 through 2028, and thereafter.

Employee Benefit Plans

6 Months Ended

Jun. 30, 2022

Note 14. Employee Benefit Plans

Multiemployer pension plans

Certain Company subsidiaries, including certain subsidiaries in Canada, contribute amounts to multiemployer pension plans and other multiemployer benefit plans and trusts, which are recorded as a component of employee wages and salaries within costs of revenues. Contributions are generally based on fixed amounts per hour per employee for employees covered under these plans. Multiemployer plan contribution rates are determined annually and assessed on a pay-as-you-go basis based on union employee payrolls. Union payrolls cannot be determined for future periods because the number of union employees employed at a given time, and the plans in which they participate, vary depending upon the location and number of ongoing projects and the need for union resources in connection with those projects. Total consolidated contributions to multiemployer plans were $27 and $24 during the three months ended June 30, 2022 and 2021, respectively, and $51 and $43 during the six months ended June 30, 2022 and 2021, respectively.

Defined benefit pension plans

The Company assumed both funded and unfunded foreign defined benefit pension plans that cover a portion of the Company's employees, and the largest plans are closed to new participants. Refer to Note 15 - "Pension" for more information on these plans.

Profit sharing plans

The Company has a trustee-administered profit sharing retirement plan covering substantially all of the Company's employees in the U.S. not covered by collective bargaining agreements and also adopted a profit sharing plan for employees in Canada (collectively, “Profit Sharing Plans”). The Profit Sharing Plans provide for annual discretionary contributions in amounts based on a performance grid as determined by the Company’s directors. In connection with these plans, the Company recognized $4 in expense during both the three months ended June 30, 2022 and 2021, and $6 and $7 in expense during the six months ended June 30, 2022 and 2021, respectively.

Employee stock purchase plan

Most of the Company’s employees in the U.S. and Canada, including named executive officers, are eligible to participate in the Company’s Employee Stock Purchase Plan (the “ESPP”). Sales of shares of the Company’s common stock under the ESPP are generally made pursuant to offerings that are intended to satisfy the requirements of Section 423 of the Internal Revenue Code. The ESPP permits employees of the Company to purchase common stock at a price equal to 85% of the lesser of (i) the market value of the common stock on the first day of the offering period, or (ii) the market value of the common stock on the purchase date, whichever is lower. Participants are subject to eligibility requirements and may not purchase more than 500 shares in any offering period or more than ten thousand dollars of common stock in a year under the ESPP. The Company recognized $1 of expense during both the three months ended June 30, 2022 and 2021, and $2 of expense during both the six months ended June 30, 2022 and 2021.

Post-retirement benefit plans

As part of the Chubb Acquisition, the Company assumed an unfunded post-retirement benefit plan that provides life benefits to certain eligible retirees in Canada. As of June 30, 2022, the benefit obligation was $4. The PBO discount rate was 3.0% at June 30, 2022.

Benefit payments, including amounts to be paid from corporate assets, and reflecting expected future service, as appropriate, are expected to be less than $1 for 2023 through 2028, and thereafter.