Revenue	12 Months Ended
Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Revenue	3. Revenue Adoption of ASC Topic 606, Revenue from Contracts with Customers On January 1, 2018, the Company adopted ASC Topic 606 using the modified retrospective transition method applied to those contracts which were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under ASC Topic 606, while prior period amounts were not adjusted and continue to be reported in accordance with ASC Topic 605, “Revenue Recognition”. The adoption of ASC Topic 606 resulted in $6 million of additional receivables and deferred revenue related to the recognition of receivables with unconditional right to payment. See Note 14 “Business Segments” for the disaggregation of revenue by reporting segments. The Company believes this disaggregation best depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. Remaining Performance Obligations Remaining performance obligations represent the transaction price of firm orders for which work has not been performed on contracts with an original expected duration of more than one year. The Company’s contracts are predominantly short-term in nature with a contract term of one year or less. For those contracts, the Company has utilized the practical expedient in ASC Topic 606 exempting the Company from disclosure of the transaction price allocated to remaining performance obligations when the performance obligation is part of a contract that has an original expected duration of one year or less. Receivables Receivables are recorded when the Company has an unconditional right to consideration. Contract Assets and Liabilities Contract assets primarily consist of retainage amounts held as a form of security by customers until the Company satisfies its remaining performance obligations. As of December 31, 2018, contracts assets were approximately $2 million and were included in receivables, net in the consolidated balance sheets. The Company applied the practical expedient to recognize the incremental costs of obtaining a contract as an expense when incurred if the amortization period of the asset that the Company otherwise would have recognized is one year or less. These expenses were not material for the year ended December 31, 2018. Contract liabilities primarily consist of deferred revenues recorded when customer payments are received or due in advance of satisfying performance obligations, including amounts which are refundable, and other accrued customer liabilities. Revenue recognition is deferred to a future period until the Company completes its obligations contractually agreed with customers. The increase in contract liabilities for the year ended December 31, 2018 was primarily related to customer deposits of approximately $16 million, partially offset by approximately $12 million of revenue recognized that was deferred at January 1, 2018 upon adoption of ASC Topic 606.

Revenue

12 Months Ended

Dec. 31, 2018

Revenue From Contract With Customer [Abstract]

3. Revenue

Adoption of ASC Topic 606, Revenue from Contracts with Customers

On January 1, 2018, the Company adopted ASC Topic 606 using the modified retrospective transition method applied to those contracts which were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under ASC Topic 606, while prior period amounts were not adjusted and continue to be reported in accordance with ASC Topic 605, “Revenue Recognition”. The adoption of ASC Topic 606 resulted in $6 million of additional receivables and deferred revenue related to the recognition of receivables with unconditional right to payment.

See Note 14 “Business Segments” for the disaggregation of revenue by reporting segments. The Company believes this disaggregation best depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors.

Remaining Performance Obligations

Remaining performance obligations represent the transaction price of firm orders for which work has not been performed on contracts with an original expected duration of more than one year. The Company’s contracts are predominantly short-term in nature with a contract term of one year or less. For those contracts, the Company has utilized the practical expedient in ASC Topic 606 exempting the Company from disclosure of the transaction price allocated to remaining performance obligations when the performance obligation is part of a contract that has an original expected duration of one year or less.

Receivables

Receivables are recorded when the Company has an unconditional right to consideration.

Contract Assets and Liabilities

Contract assets primarily consist of retainage amounts held as a form of security by customers until the Company satisfies its remaining performance obligations. As of December 31, 2018, contracts assets were approximately $2 million and were included in receivables, net in the consolidated balance sheets. The Company applied the practical expedient to recognize the incremental costs of obtaining a contract as an expense when incurred if the amortization period of the asset that the Company otherwise would have recognized is one year or less. These expenses were not material for the year ended December 31, 2018.

Contract liabilities primarily consist of deferred revenues recorded when customer payments are received or due in advance of satisfying performance obligations, including amounts which are refundable, and other accrued customer liabilities. Revenue recognition is deferred to a future period until the Company completes its obligations contractually agreed with customers. The increase in contract liabilities for the year ended December 31, 2018 was primarily related to customer deposits of approximately $16 million, partially offset by approximately $12 million of revenue recognized that was deferred at January 1, 2018 upon adoption of ASC Topic 606.