QUARTERLY RESULTS OF OPERATIONS - UNAUDITED (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 229,351	$ 260,024	$ 216,421	$ 186,024	$ 235,002	$ 246,008	$ 223,797	$ 205,111	$ 891,820	$ 909,918	$ 986,787
Gross profit	166,619	194,439	157,289	131,281	176,466	176,424	159,817	143,084	649,628	655,791	714,882
Net income (loss)	$ 7,336	$ 36,725	$ (17,472)	$ (29,343)	$ 19,211	$ (3,603)	$ (26,428)	$ (62,504)	$ (2,754)	$ (73,324)	$ 79,812
Diluted net income (loss) per share (in dollars per share)	$ 0.10	$ 0.49	$ (0.23)	$ (0.38)	$ 0.24	$ (0.05)	$ (0.34)	$ (0.78)	$ (0.04)	$ (0.93)	$ 0.90