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Quarterly Financial Data (Unaudited) - Narratives (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Oct. 24, 2015 | Jan. 27, 2018 | Jul. 29, 2017 | Jul. 30, 2016 | Jul. 25, 2015 | Jul. 15, 2015
Interim Period, Costs Not Allocable [Line Items] |  |  |  |  |  |
Tax Cuts and Jobs Act of 2017, adjustment to income tax liability |  | $ 32.2 |  |  |  |
Tax benefit from exercise of stock options |  | $ 7.8 |  |  |  |
Debt extinguishment cost | $ 16.3 |  |  |  |  |
7.125% Senior Subordinated Notes |  |  |  |  |  |
Interim Period, Costs Not Allocable [Line Items] |  |  |  |  |  |
Debt, interest rate (in percent) | 7.125% |  |  | 7.125% | 7.125% | 7.125%

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