CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2023	Jul. 31, 2022	Jul. 31, 2023	Jul. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 12,767	$ 4,222	$ 14,876	$ 11,707
Adjustments to reconcile net income to net cash used in operating activities
Stock compensation expense	1,200	1,100	2,218	1,979
Depreciation	488	747	1,035	1,556
Lease expense	400	500	884	1,319
Changes in accrued interest on investments			(341)	(617)
Deferred income tax (benefit) expense			(196)	373
Amortization of intangible assets	98	233	196	399
Equity in loss (income) of solar energy investments			98	(1,070)
Other			64	8
Changes in operating assets and liabilities
Accounts receivable			5,600	2,090
Contract assets			4,031	(3,774)
Other assets			(5,176)	9,252
Accounts payable and accrued expenses			(8,931)	(16,124)
Contract liabilities			20,195	(63,874)
Net cash provided by (used in) operating activities			34,553	(56,776)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of short-term investments			(90,000)	(175,000)
Maturities of short-term investments			159,750	90,000
Purchases of available-for-sale securities			(60,261)
Purchases of property, plant and equipment			(1,031)	(638)
Net cash provided by (used in) investing activities			8,458	(85,638)
CASH FLOWS FROM FINANCING ACTIVITIES
Common stock repurchases			(6,738)	(53,168)
Payments of cash dividends			(6,699)	(7,192)
Proceeds from the exercise of stock options			947	66
Net cash used in financing activities			(12,490)	(60,294)
EFFECTS OF EXCHANGE RATE CHANGES ON CASH			331	(4,420)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS			30,852	(207,128)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			173,947	350,472
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 204,799	$ 143,344	$ 204,799	$ 143,344