INCOME TAXES - UNCERTAIN TAX POSITIONS (Details) - USD ($)	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Increase in interest and penalties	$ 2,363,000	$ 877,000	$ 1,098,000
Gross amount of interest and penalties accrued	6,453,000	4,090,000
Possible decrease in unrecognized tax benefits	8,400,000
Aggregate changes to the liability for gross uncertain tax position, excluding interest and penalties
Balance, beginning of period	116,085,000	52,799,000	40,591,000
Additions:
Current year tax positions	23,007,000	65,669,000	12,208,000
Prior year tax positions	7,406,000	5,086,000	0
Reduction of prior year tax positions	(436,000)	0	0
Lapse of statute of limitations	(24,006,000)	(7,469,000)	0
Balance, end of period	$ 122,056,000	$ 116,085,000	$ 52,799,000