Reportable Operating Segments (Details)	3 Months Ended		6 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) segment	Sep. 30, 2018 USD ($)	Mar. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			6
Net sales	$ 542,205,000	$ 501,913,000	$ 819,044,000	$ 752,507,000
(Loss) income from operations	97,131,000	90,412,000	65,714,000	50,998,000
Total assets	1,691,659,000		1,691,659,000		$ 1,427,206,000
Unallocated cash and cash equivalents	177,673,000		177,673,000		589,692,000
Unallocated deferred tax assets, net	31,253,000		31,253,000		30,870,000
Reportable segments
Segment Reporting Information [Line Items]
Total assets	1,165,655,000		1,165,655,000		592,342,000
Reportable segments | UGG brand wholesale
Segment Reporting Information [Line Items]
Total assets	691,484,000		691,484,000		240,411,000
Reportable segments | HOKA brand wholesale
Segment Reporting Information [Line Items]
Total assets	84,589,000		84,589,000		94,157,000
Reportable segments | Teva brand wholesale
Segment Reporting Information [Line Items]
Total assets	39,521,000		39,521,000		76,370,000
Reportable segments | Sanuk brand wholesale
Segment Reporting Information [Line Items]
Total assets	44,534,000		44,534,000		71,285,000
Reportable segments | Other brands wholesale
Segment Reporting Information [Line Items]
Total assets	65,479,000		65,479,000		14,618,000
Reportable segments | Direct-to-Consumer
Segment Reporting Information [Line Items]
Total assets	240,048,000		240,048,000		95,501,000
Segment reconciling items
Segment Reporting Information [Line Items]
Intersegment profit			0
(Loss) income from operations	(66,240,000)	(62,187,000)	(124,267,000)	(118,388,000)
Unallocated other corporate assets	317,078,000		317,078,000		$ 214,302,000
Wholesale | UGG brand wholesale
Segment Reporting Information [Line Items]
Net sales	332,020,000	319,589,000	417,420,000	400,942,000
Wholesale | HOKA brand wholesale
Segment Reporting Information [Line Items]
Net sales	60,959,000	43,561,000	124,965,000	83,515,000
Wholesale | Teva brand wholesale
Segment Reporting Information [Line Items]
Net sales	17,091,000	15,878,000	47,922,000	49,074,000
Wholesale | Sanuk brand wholesale
Segment Reporting Information [Line Items]
Net sales	8,166,000	10,933,000	22,773,000	31,436,000
Wholesale | Other brands wholesale
Segment Reporting Information [Line Items]
Net sales	25,282,000	18,064,000	27,009,000	20,701,000
Wholesale | Reportable segments | UGG brand wholesale
Segment Reporting Information [Line Items]
(Loss) income from operations	135,663,000	134,029,000	145,104,000	139,898,000
Wholesale | Reportable segments | HOKA brand wholesale
Segment Reporting Information [Line Items]
(Loss) income from operations	14,054,000	8,170,000	25,412,000	13,898,000
Wholesale | Reportable segments | Teva brand wholesale
Segment Reporting Information [Line Items]
(Loss) income from operations	3,523,000	1,847,000	11,839,000	9,911,000
Wholesale | Reportable segments | Sanuk brand wholesale
Segment Reporting Information [Line Items]
(Loss) income from operations	238,000	291,000	2,173,000	4,491,000
Wholesale | Reportable segments | Other brands wholesale
Segment Reporting Information [Line Items]
(Loss) income from operations	6,958,000	5,287,000	7,090,000	5,637,000
Directly to Consumer | Direct-to-Consumer
Segment Reporting Information [Line Items]
Net sales	98,687,000	93,888,000	178,955,000	166,839,000
Directly to Consumer | Reportable segments | Direct-to-Consumer
Segment Reporting Information [Line Items]
(Loss) income from operations	$ 2,935,000	$ 2,975,000	$ (1,637,000)	$ (4,449,000)