Discontinued Operations Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Related Party Transaction [Line Items]
Arcosa TSA Net Receivable	$ 6.4
Revenue from Related Parties	9.5
Related Party Transaction, Purchases from Related Party	13.3
Accounts Receivable, Related Parties	9.8
Accounts Payable, Related Parties	5.2
Business Combination, Separately Recognized Transactions, Expenses and Losses Recognized	1.0	$ 7.9
Disposal Group Classification [Domain]
Related Party Transaction [Line Items]
Business Combination, Separately Recognized Transactions, Expenses and Losses Recognized	$ 1.0	$ 7.4

Arcosa TSA Net Receivable

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- Definition

Amount for accounts payable to related parties.

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For an unclassified balance sheet, amount of receivables arising from transactions with related parties.

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The expenses and losses recorded for each transaction with the acquiree that was recognized separately from the acquisition of assets and assumptions of liabilities in the business combination.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Purchases during the period (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

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Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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