Commitments and Contingencies (Narrative) (Details) $ in Millions	3 Months Ended	9 Months Ended
	Oct. 28, 2017 USD ($) ft²	Oct. 28, 2017 USD ($) ft² lease
Other Commitments [Line Items]
Number Of Leases | lease		24
Lessee Leasing Arrangements, Operating Leases, Term of Contract		10 years
Purchase Commitment, Remaining Minimum Amount Committed	$ 5.3	$ 5.3
Long-term Purchase Commitment, Amount	$ 42.9
Operating Leases, Rent Expense, Minimum Rentals		$ 50.0
Lessee Leasing Arrangements, Operating Leases, Renewal Term		5 years
Description of Lessee Leasing Arrangements, Operating Leases		10 to 15
Minimum [Member]
Other Commitments [Line Items]
Area of Real Estate Property | ft²	115,000	115,000
Maximum [Member]
Other Commitments [Line Items]
Area of Real Estate Property | ft²	20,000	20,000
Lease Agreements [Member]
Other Commitments [Line Items]
Lessee Leasing Arrangements, Operating Leases, Term of Contract		15 years
Lessee Leasing Arrangements, Operating Leases, Renewal Term		15 years