Condensed Consolidated Statements of Cash Flows (USD $)	6 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Cash flows from operating activities:
Net earnings	$ 5,286,000	$ 5,193,000
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	1,462,000	2,085,000
Stock-based compensation expense	700,000	775,000
Bond amortization	1,000	11,000
Tax benefit of stock options exercised	88,000	86,000
Excess tax benefits from stock-based compensation	(68,000)	(70,000)
Net loss on investments	350,000	183,000
Retirement of property and equipment		15,000
Deferred income taxes	(103,000)	(294,000)
Changes in operating assets and liabilities:
Purchases of trading securities	(7,412,000)	(8,074,000)
Proceeds from maturities and sales of trading securities	11,152,000	9,732,000
Accounts receivable, net	(118,000)	1,436,000
Prepaid expenses and other assets	(429,000)	(91,000)
Accounts payable and other liabilities	165,000	(3,269,000)
Deferred revenue	(1,438,000)	(1,474,000)
Net cash provided by operating activities	9,636,000	6,244,000
Cash flows from investing activities:
Capitalized computer software development costs	(1,641,000)	(1,811,000)
Purchases of property and equipment, net of disposals	(155,000)	(521,000)
Proceeds from maturities of investments	225,000	693,000
Purchase of business, net of cash acquired	(1,191,000)
Net cash used in investing activities	(2,762,000)	(1,639,000)
Cash flows from financing activities:
Repurchase of common stock		(254,000)
Excess tax benefits from stock based compensation	68,000	70,000
Proceeds from exercise of stock options	1,120,000	912,000
Dividends paid		(4,887,000)
Net cash provided by (used in) financing activities	1,188,000	(4,159,000)
Net change in cash and cash equivalents	8,062,000	446,000
Cash and cash equivalents at beginning of period	41,164,000	39,111,000
Cash and cash equivalents at end of period	$ 49,226,000	$ 39,557,000