Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 66,365,000	$ 66,410,000	$ 46,356,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	25,121,000	23,916,000	23,436,000
Loss on write down or disposal of property, capitalized software or investment	415,000	122,000	590,000
Stock compensation expense	5,559,000	5,198,000	4,978,000
Provision for doubtful accounts	1,216,000	158,000	2,021,000
Deferred income taxes	(1,913,000)	2,302,000	(8,376,000)
Changes in operating assets and liabilities:
Accounts receivable	336,000	(18,022,000)	(976,000)
Customer deposits	(10,241,000)	(13,284,000)	(7,507,000)
Prepaid expenses and income taxes	3,738,000	(7,116,000)	3,003,000
Other assets	(919,000)	(135,000)	504,000
Accounts and income taxes payable	(4,395,000)	1,423,000	(3,355,000)
Accrued liabilities	(4,361,000)	8,052,000	31,561,000
Operating lease liabilities	1,367,000	(1,802,000)	2,144,000
Net cash provided by operating activities	82,288,000	67,222,000	94,379,000
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(26,320,000)	(29,819,000)	(17,243,000)
Net cash used in investing activities	(26,320,000)	(29,819,000)	(17,243,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Exercise of employee stock purchase options	676,000	564,000	534,000
Exercise of common stock options	10,856,000	9,906,000	11,494,000
Purchase of treasury stock	(93,675,000)	(90,085,000)	(32,671,000)
Net cash used in financing activities	(82,143,000)	(79,615,000)	(20,643,000)
Net (decrease) increase in cash and cash equivalents	(26,175,000)	(42,212,000)	56,493,000
Cash and cash equivalents at beginning of year	97,504,000	139,716,000	83,223,000
CASH AND CASH EQUIVALENTS AT END OF YEAR	71,329,000	97,504,000	139,716,000
Supplemental cash flow information
Income taxes paid	19,993,000	19,405,000	20,760,000
Accrual of software license purchase	$ 5,273,000	$ 0	$ 0