PROPERTY AND EQUIPMENT - Property and Equipment at Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 163,710	$ 120,140
Less: accumulated depreciation	60,131	38,469
Property and equipment, net	$ 103,579	81,671
Machinery and equipment
Property, Plant and Equipment [Line Items]
Estimated useful lives of fixed assets	5 years
Property and equipment, gross	$ 1,820	1,195
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 78,082	67,066
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives of fixed assets	3 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of fixed assets	13 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 70,899	43,440
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives of fixed assets	3 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of fixed assets	5 years
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 12,909	$ 8,439
Computer equipment and software | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives of fixed assets	2 years
Computer equipment and software | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of fixed assets	3 years