ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES: - Narrative (Details) $ in Thousands	12 Months Ended
	Mar. 31, 2021 USD ($) segment reportingUnit	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2022 USD ($)	Apr. 01, 2021 USD ($)	Mar. 31, 2018 USD ($)
Property, Plant and Equipment [Line Items]
Number of operating segments | segment	1
Unbilled amounts included in accounts receivable	$ 8,000	$ 5,000
Capitalized contract cost amortization period	4 years
Recognition of capitalized contract cost	$ 6,600	5,300
Right-of-use asset (see Note 3)	11,731	17,830
Short-term lease liabilities (see Note 3)	9,608	9,641
Long-term lease liabilities	$ 4,158	11,449
Number of reporting units | reportingUnit	3
Advertising expense	$ 7,000	$ 9,800	$ 8,200
Scenario, Forecast | Tax Year 2020
Property, Plant and Equipment [Line Items]
Income tax examination, refund adjustment from settlement with taxing authority				$ 33,000
Scenario, Forecast | Tax Year 2021
Property, Plant and Equipment [Line Items]
Income tax examination, refund adjustment from settlement with taxing authority				$ 28,000	$ 28,000
Revenue Benchmark | Customer Concentration Risk | Ten Largest Customers
Property, Plant and Equipment [Line Items]
Concentration risk, percentage	33.00%
Revenue Benchmark | Customer Concentration Risk | Interpublic Group of Companies
Property, Plant and Equipment [Line Items]
Concentration risk, percentage	11.00%
Cumulative Effect, Period of Adoption, Adjustment
Property, Plant and Equipment [Line Items]
Right-of-use asset (see Note 3)						$ 22,900
Short-term lease liabilities (see Note 3)						8,400
Long-term lease liabilities						17,900
Deferred rent						$ 3,400
Minimum | Incentive Stock Option
Property, Plant and Equipment [Line Items]
Exercise price as a percentage of the per-share market value of the Company's shares at the date of grant	100.00%
Minimum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Minimum | Data processing equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	2 years
Minimum | Office furniture and other equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Maximum | Incentive Stock Option
Property, Plant and Equipment [Line Items]
Duration of stock options granted	10 years
Maximum | Nonqualified Options
Property, Plant and Equipment [Line Items]
Exercise price as a percentage of the per-share market value of the Company's shares at the date of grant	100.00%
Duration of stock options granted	10 years
Maximum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years
Maximum | Data processing equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Maximum | Office furniture and other equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years