Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 76,252,000	$ 66,365,000	$ 66,410,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	26,252,000	25,121,000	23,916,000
Loss on write down or disposal of property, capitalized software or investment	290,000	415,000	122,000
Stock compensation expense	4,982,000	5,559,000	5,198,000
Provision for expected credit losses	1,828,000	1,216,000	158,000
Deferred income taxes	(3,321,000)	(1,913,000)	2,302,000
Changes in operating assets and liabilities:
Accounts receivable	(17,902,000)	336,000	(18,022,000)
Customer deposits	(8,120,000)	(10,241,000)	(13,284,000)
Prepaid expenses and income taxes	(32,000)	3,738,000	(7,116,000)
Other assets	60,000	(919,000)	(135,000)
Accounts and income taxes payable	(1,322,000)	(4,395,000)	1,423,000
Accrued liabilities	15,290,000	(4,361,000)	8,052,000
Operating lease liabilities	2,336,000	1,367,000	(1,802,000)
Net cash provided by operating activities	99,237,000	82,288,000	67,222,000
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(29,240,000)	(26,320,000)	(29,819,000)
Net cash used in investing activities	(29,240,000)	(26,320,000)	(29,819,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Exercise of employee stock purchase options	681,000	676,000	564,000
Exercise of common stock options	9,266,000	10,856,000	9,906,000
Purchase of treasury stock	(45,710,000)	(93,675,000)	(90,085,000)
Net cash used in financing activities	(35,763,000)	(82,143,000)	(79,615,000)
Net increase (decrease) in cash and cash equivalents	34,234,000	(26,175,000)	(42,212,000)
Cash and cash equivalents at beginning of year	71,329,000	97,504,000	139,716,000
CASH AND CASH EQUIVALENTS AT END OF YEAR	105,563,000	71,329,000	97,504,000
Supplemental cash flow information
Income taxes paid	22,874,000	19,993,000	19,405,000
Accrual of software license purchase	$ 0	$ 5,273,000	$ 0