Accounts Receivable (Details) - USD ($) $ in Thousands	Apr. 25, 2020	Jan. 25, 2020	Apr. 27, 2019	Jan. 26, 2019
Receivables [Abstract]
Contract with Customer, Asset, Net	$ 250,435	$ 236,673
Trade accounts receivable	384,383	355,805
Unbilled accounts receivable	479,706	453,353
Retainage	11,868	12,669
Total	875,957	821,827
Less: allowance for doubtful accounts	(5,166)	(4,582)	$ (1,372)	$ (17,702)
Less: allowance for doubtful accounts		(4,582)
Accounts receivable, net	$ 870,791	$ 817,245

Contract Receivable Retainage and Other Receivables

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- Definition

Amount, before allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business.

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Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business.

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Amount of allowance for credit loss on accounts receivable.

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Amount of allowance for credit loss on accounts receivable, classified as current.

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- Definition

Amounts due for billed services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the Company and, at a minimum, one other party. An example would be amounts billed to customers under contracts or programs but not paid as of the balance sheet date.

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Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

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Unbilled amounts due for services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the entity and, at a minimum, one other party. An example would be amounts associated with contracts or programs where the recognized revenue for performance thereunder exceeds the amounts billed under the terms thereof as of the date of the balance sheet.

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