Segments - Information regarding reportable segments (Details) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended
		Jul. 31, 2018	Jul. 31, 2017		Jul. 31, 2018	Jul. 31, 2017
Segment Reporting Information [Line Items]
Net sales		$ 624,698	$ 538,006	[1]	$ 1,236,441	$ 1,067,048	[1]
Cost of goods sold		393,154	335,016	[2]	770,370	662,343	[2]
Gross profit		231,544	202,990		466,071	404,705
Selling, general and administrative expenses		198,860	195,849		400,931	393,260
Depreciation and amortization		9,455	10,736		18,835	20,574
Operating profit (loss)		23,229	(3,595)		46,305	(9,129)
Operating Segments | Wholesale
Segment Reporting Information [Line Items]
Net sales		544,597	467,769	[1]	1,072,270	921,083	[1]
Cost of goods sold		362,756	316,435	[2]	704,331	614,737	[2]
Gross profit		181,841	151,334		367,939	306,346
Selling, general and administrative expenses		136,178	128,484		272,591	258,644
Depreciation and amortization		7,348	7,229		14,483	13,614
Operating profit (loss)		38,315	15,621		80,865	34,088
Operating Segments | Retail
Segment Reporting Information [Line Items]
Net sales		106,662	106,436	[1]	211,181	205,620	[1]
Cost of goods sold		56,959	54,780	[2]	113,049	107,261	[2]
Gross profit		49,703	51,656		98,132	98,359
Selling, general and administrative expenses		62,682	67,365		128,340	134,616
Depreciation and amortization		2,107	3,507		4,352	6,960
Operating profit (loss)		(15,086)	(19,216)		(34,560)	(43,217)
Elimination
Segment Reporting Information [Line Items]
Net sales	[3]	(26,561)	(36,199)	[1]	(47,010)	(59,655)	[1]
Cost of goods sold	[3]	(26,561)	(36,199)	[2]	(47,010)	(59,655)	[2]
Gross profit	[3]	0	0		0	0
Selling, general and administrative expenses	[3]	0	0		0	0
Depreciation and amortization	[3]	0	0		0	0
Operating profit (loss)	[3]	$ 0	$ 0		$ 0	$ 0

[1] Certain reclassifications have been made between the wholesale operations segment and the elimination column as a result of sales eliminations within the wholesale operations segment being misclassified as inter-segment eliminations.

[2] Certain reclassifications have been made as a result of the Company's reclassifying the impact of certain components of foreign currency gain (loss) from cost of goods sold and interest expense to other income.

[3] Represents intersegment sales to the Company's retail operations.