SEGMENT AND GEOGRAPHIC INFORMATION - REVENUE BY DISTRIBUTION CHANNEL (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Net revenue by distribution channel:
Net revenue	$ 571,555	$ 476,474	$ 420,167	$ 311,552	$ 377,206	$ 414,221	$ 346,974	$ 275,297	$ 1,779,748	$ 1,413,698	$ 1,082,938
Digital online
Net revenue by distribution channel:
Net revenue									921,734	697,658	455,299
Physical retail and other
Net revenue by distribution channel:
Net revenue									$ 858,014	$ 716,040	$ 627,639