PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 10,400	$ 5,800
Accelerated depreciation	3,600
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	64,440		$ 64,852
Less accumulated depreciation and amortization	43,278		38,809
Property and equipment, net of accumulated depreciation and amortization	21,162		26,043
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	23,981		20,097
Data processing equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	31,785		37,678
Office furniture and other equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 8,674		$ 7,077