CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2021	Jul. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 12,870	$ 5,599	$ 23,636	$ 4,806
Adjustments to reconcile net income to net cash provided by operating activities
Lease expense	1,100	400	1,938	793
Depreciation	859	921	1,741	1,858
Stock compensation expense	900	800	1,609	1,414
Deferred income tax expense			1,001	8,536
Amortization of purchased intangible assets	225	226	453	451
Other			229	399
Changes in operating assets and liabilities
Accounts receivable			(14,407)	7,532
Contract assets			1,258	6,856
Other assets			(3,161)	(17,781)
Accounts payable and accrued expenses			(8,793)	4,714
Contract liabilities			41,680	83,323
Net cash provided by operating activities			47,184	102,901
CASH FLOWS FROM INVESTING ACTIVITIES
Maturities of short-term investments			50,000	145,000
Purchase of short-term investment				(10,000)
Investment in solar energy project			(4,085)
Purchases of property, plant and equipment			(1,011)	(1,133)
Net cash provided by investing activities			44,904	133,867
CASH FLOWS FROM FINANCING ACTIVITIES
Payments of cash dividends			(7,884)	(23,499)
Proceeds from the exercise of stock options			1,023	725
Net cash used in financing activities			(6,861)	(22,774)
EFFECTS OF EXCHANGE RATE CHANGES ON CASH			(483)	1,067
NET INCREASE IN CASH AND CASH EQUIVALENTS			84,744	215,061
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			366,671	167,363
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 451,415	$ 382,424	$ 451,415	$ 382,424