Accounts Receivable, Contract Assets, and Contract Liabilities - Change in Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 25, 2020	Jul. 27, 2019	Jul. 25, 2020	Jul. 27, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for doubtful accounts at beginning of period	$ 5,166	$ 1,372	$ 4,582	$ 17,702
Provision for bad debt (recovery)	119	(202)	236	(10,514)
Amounts recovered (charged) against the allowance	(3,680)	(246)	(3,684)	(6,264)
Allowance for doubtful accounts at end of period	1,605	924	1,605	924
Cumulative Effect, Period Of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for doubtful accounts at beginning of period			471
Allowance for doubtful accounts at end of period	$ 0	$ 0	0	$ 0
Windstream Corporation
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for doubtful accounts at beginning of period			$ 16,800