SEGMENT AND GEOGRAPHIC INFORMATION - Summary of Total Revenue by Geography (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]
Total revenue	$ 119,385	$ 122,833	$ 103,599	$ 107,852	$ 112,317	$ 110,428	$ 92,097	$ 81,805	$ 453,669	$ 396,647	$ 350,550
United States
Segment Reporting Information [Line Items]
Total revenue									348,354	303,364	262,020
Europe
Segment Reporting Information [Line Items]
Total revenue									46,253	45,837	42,884
Asia
Segment Reporting Information [Line Items]
Total revenue									27,685	20,646	18,107
Rest of the world
Segment Reporting Information [Line Items]
Total revenue									$ 31,377	$ 26,800	$ 27,539