Stock-Based Awards - Tax Benefit Recognized (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jan. 27, 2018	Jan. 26, 2019	Jul. 29, 2017	Jul. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based compensation	$ 13,277	$ 20,187	$ 20,805	$ 16,850
Recognized tax benefit of stock-based compensation	$ 4,793	$ 5,043	$ 7,996	$ 6,436

The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Name:	us-gaap_ShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration