Revenue

3 Months Ended

Mar. 31, 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 and greenhouse structures; electrical balance of systems; extraction systems; roof and foundation ventilation products; centralized mail systems and electronic package solutions; rain dispersion products and roofing accessories; retractable awnings; gutter guards; expansion joints and structural bearings.

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

As of March 31, 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 March 31, 2021 and December 31, 2020 was $13.1 million and $21.3 million, respectively. Revenue recognized during the three months ended March 31, 2021 and 2020 that was in contract liabilities at the beginning of the respective periods was $40.7 million and $38.1 million, respectively.