Transition Period (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended									6 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Mar. 31, 2014	Mar. 31, 2013	Jun. 30, 2014	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2013
Transition Period [Abstract]
Net sales	$ 378,635	$ 795,902	$ 486,855	$ 213,805	$ 340,637	$ 784,678	$ 480,273	$ 294,716	$ 263,760	$ 211,469	$ 1,875,197	$ 1,817,057	$ 1,556,618
Cost of sales								150,456	140,201		1,028,529	938,949	820,135
Gross profit	$ 154,942	$ 391,017	$ 214,113	$ 86,596	$ 152,324	$ 415,139	$ 223,873	144,260	123,559	$ 86,772	846,668	878,108	736,483
Selling, general and administrative expenses								144,668	120,907		684,541	653,689	528,586
Income (loss) from operations								(408)	2,652		162,127	224,419	207,897
Other expense (income), net:
Interest income								(65)	(26)		(420)	(207)	(60)
Interest expense								516	339		5,814	4,220	3,079
Other, net								(117)	(171)		(152)	(733)	(679)
Total other expense, net								334	142		5,242	3,280	2,340
(Loss) income before income taxes								(742)	2,510		156,885	221,139	205,557
Income tax expense								1,943	1,503		34,620	59,359	59,868
Net income (loss)								(2,685)	1,007		122,265	161,780	145,689
Other comprehensive (loss) income, net of tax:
Unrealized (loss) gain on foreign currency hedging								(273)	1,530		461	450	(486)
Foreign currency translation adjustment								873	(674)		(550)	(18,875)	(757)
Total other comprehensive (loss) income								600	856		(89)	(18,425)	(1,243)
Comprehensive income (loss)								$ (2,085)	$ 1,863		$ 122,176	$ 143,355	$ 144,446
Net (loss) income per share:
Basic (in dollars per share)	$ (0.73)	$ 4.85	$ 1.12	$ (1.43)	$ 0.04	$ 4.54	$ 1.18	$ (0.08)	$ 0.03	$ (1.07)	$ 3.76	$ 4.70	$ 4.23
Diluted (in dollars per share)	$ (0.73)	$ 4.78	$ 1.11	$ (1.43)	$ 0.04	$ 4.50	$ 1.17	$ (0.08)	$ 0.03	$ (1.07)	$ 3.70	$ 4.66	$ 4.18
Weighted-average common shares outstanding:
Basic (in shares)								34,621	34,404		32,556	34,433	34,473
Diluted (in shares)								34,621	34,788		33,039	34,733	34,829