Revenue

6 Months Ended

Jun. 30, 2021

Revenue from Contract with Customer [Abstract]

Revenue

REVENUE

Sales includes revenue from contracts with customers for: designing, engineering, manufacturing and installation of solar racking systems; electrical balance of systems; roof and foundation ventilation products; centralized mail systems and electronic package solutions; retractable awnings; gutter guards; rain dispersion products; trims and flashings and other accessories; designing, engineering, manufacturing and installation of greenhouses; botanical extraction systems; structural bearings; expansion joints; pavement sealant; elastomeric concrete; and bridge cable protection systems.

Refer to Note 15 "Segment Information" for additional information related to revenue recognized by timing of transfer of control by reportable segment.

As of June 30, 2021, the Company's remaining performance obligations are part of contracts that have an original expected duration of one year or less.

Contract assets consist of costs in excess of billings. Contract liabilities consist of billings in excess of cost and unearned revenue. Unearned revenue as of June 30, 2021 and December 31, 2020 was $4.7 million and $21.3 million, respectively. Revenue recognized during the three months ended June 30, 2021 and 2020 that was in contract liabilities at the beginning of the respective periods was $49.2 million and $53.3 million, respectively.