CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ 10,766	$ (793)
Adjustments to reconcile net income (loss) to net cash provided by operating activities
Deferred income tax expense	599	8,214
Depreciation	882	937
Stock compensation expense	679	642
Lease expense	776	379
Amortization of purchased intangible assets	228	225
Other	(114)	328
Changes in operating assets and liabilities
Accounts receivable	(3,666)	14,980
Contract assets	477	344
Other assets	765	(13,600)
Accounts payable and accrued expenses	(21,552)	(8,609)
Contract liabilities	27,506	37,140
Net cash provided by operating activities	17,346	40,187
CASH FLOWS FROM INVESTING ACTIVITIES
Maturities of short-term investments	20,000	70,000
Purchases of short-term investments		(10,000)
Investment in solar energy projects	(3,520)
Purchases of property, plant and equipment	(844)	(684)
Net cash provided by investing activities	15,636	59,316
CASH FLOWS FROM FINANCING ACTIVITIES
Payments of cash dividends	(3,942)	(3,910)
Proceeds from the exercise of stock options	1,023	177
Net cash used in financing activities	(2,919)	(3,733)
EFFECTS OF EXCHANGE RATE CHANGES ON CASH	(59)	(206)
NET INCREASE IN CASH AND CASH EQUIVALENTS	30,004	95,564
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	366,671	167,363
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 396,675	$ 262,927