Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 29,479,000	$ 28,525,000	$ 28,590,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	20,948,000	19,952,000	17,995,000
Loss on write down or disposal of property or capitalized software	733,000	286,000	285,000
Stock-based compensation expense	2,432,000	2,192,000	2,209,000
Provision for doubtful accounts	2,335,000	1,357,000	1,730,000
Provision for deferred income taxes	(1,220,000)	(1,656,000)	304,000
Changes in operating assets and liabilities:
Accounts receivable	(5,429,000)	(3,567,000)	(2,038,000)
Customer deposits	(6,822,000)	(8,331,000)	(1,176,000)
Prepaid expenses and taxes	(11,000)	6,742,000	(5,813,000)
Other assets	(29,000)	(516,000)	(18,000)
Accounts and taxes payable	3,350,000	(2,537,000)	(2,695,000)
Accrued liabilities	6,286,000	8,864,000	4,943,000
Net cash provided by operating activities	52,052,000	51,311,000	44,316,000
CASH FLOWS FROM INVESTING ACTIVITIES
Investment in private equity	34,000	(600,000)	(1,400,000)
Purchases of property and equipment	(31,041,000)	(16,756,000)	(22,868,000)
Net cash used in investing activities	(31,007,000)	(17,356,000)	(24,268,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Exercise of employee stock purchase options	419,000	371,000	400,000
Exercise of common stock options	2,367,000	3,749,000	1,603,000
Tax benefits from stock options	0	713,000	397,000
Purchase of treasury stock	(27,999,000)	(31,525,000)	(31,798,000)
Net cash used in financing activities	(25,213,000)	(26,692,000)	(29,398,000)
Net increase (decrease) in cash and cash equivalents	(4,168,000)	7,263,000	(9,350,000)
Cash and cash equivalents at beginning of year	32,779,000	25,516,000	34,866,000
CASH AND CASH EQUIVALENTS AT END OF YEAR	28,611,000	32,779,000	25,516,000
Supplemental cash flow information
Income taxes paid	18,321,000	13,589,000	19,528,000
Accrual of software license purchase	3,492,000	3,249,000	0
Tenant improvement allowance	$ 1,224,000	$ 0	$ 3,100,000