Accounts Receivable Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 25, 2020	Apr. 27, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for doubtful accounts at beginning of period	$ 4,582	$ 17,702
Provision for bad debt (recovery)	118	(10,311)
Amounts recovered (charged) against the allowance	(5)	(6,019)
Allowance for doubtful accounts at end of period	5,166	$ 1,372
Cumulative Effect, Period Of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for doubtful accounts at beginning of period	471
Windstream Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for doubtful accounts at beginning of period	$ 16,800