RECENT ACCOUNTING PRONOUNCEMENTS - Cumulative Effect of Adoption of Topic 606 on Statements Of Operations and Statements Of Comprehensive Income (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	$ 468,488	$ 501,669	$ 483,069	$ 221,309	$ 216,143	$ 226,534	$ 210,300	$ 203,926	$ 1,674,535	$ 856,903	$ 881,176
Gross profit	216,530	215,137	152,629	109,843	114,075	114,125	107,632	103,283	694,139	439,115	441,370
Selling, general, and administrative									567,879	229,390	223,830
Total operating expenses									803,434	315,614	316,294
Operating income (loss)									(109,295)	123,501	125,076
Income (loss) before income taxes									(185,692)	100,227	101,665
Income tax expense (benefit)									(50,131)	101,096	19,066
Net income (loss)	$ (21,589)	$ (41,734)	$ (86,709)	$ 14,471	$ 9,854	$ (49,504)	$ 19,953	$ 18,828	$ (135,561)	$ (869)	$ 82,599
Basic earnings (loss) per common share (in dollars per share)	$ (0.55)	$ (1.06)	$ (2.21)	$ 0.43	$ 0.30	$ (1.54)	$ 0.59	$ 0.58	$ (3.61)	$ (0.03)	$ 2.56
Diluted earnings (loss) per common share (in dollars per share)	$ (0.55)	$ (1.06)	$ (2.21)	$ 0.42	$ 0.29	$ (1.54)	$ 0.59	$ 0.57	$ (3.61)	$ (0.03)	$ 2.51
Comprehensive income (loss)									$ (138,905)	$ (2,693)	$ 83,534
Product [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues									1,510,770
Service [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues									163,765	$ 0	$ 0
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues									1,674,786
Gross profit									694,390
Selling, general, and administrative									570,949
Total operating expenses									806,504
Operating income (loss)									(112,114)
Income (loss) before income taxes									(188,511)
Income tax expense (benefit)									(50,440)
Net income (loss)									$ (138,071)
Basic earnings (loss) per common share (in dollars per share)									$ (3.68)
Diluted earnings (loss) per common share (in dollars per share)									$ (3.68)
Comprehensive income (loss)									$ (141,415)
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Product [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues									1,509,423
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Service [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues									165,363
Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues									251
Gross profit									251
Selling, general, and administrative									3,070
Total operating expenses									3,070
Operating income (loss)									(2,819)
Income (loss) before income taxes									(2,819)
Income tax expense (benefit)									(309)
Net income (loss)									$ (2,510)
Basic earnings (loss) per common share (in dollars per share)									$ (0.07)
Diluted earnings (loss) per common share (in dollars per share)									$ (0.07)
Comprehensive income (loss)									$ (2,510)
Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Product [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues									(1,347)
Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Service [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues									$ 1,598