Summary of Significant Accounting Policies (Property and Equipment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 28, 2017	Jan. 30, 2016	Jan. 31, 2015
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 26,631	$ 22,227	$ 17,202
Property and equipment, gross	238,576	194,179
Less: Accumulated depreciation and amortization	(100,200)	(74,395)
Property and equipment, net	138,376	119,784
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 96,491	81,418
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Property and equipment, gross	$ 96,075	80,814
Computer and equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	36,159	28,358
Construction in process [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 9,851	$ 3,589
Minimum [Member] | Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Maximum [Member] | Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years