CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income	$ (33,494)	$ 54,160
Adjustments to reconcile net (loss) income to net cash provided by (used in) operating activities
Deferred income tax benefit	(4,521)	(153)
Impairment loss	2,072
Depreciation	2,610	2,465
Stock compensation expense	1,512	1,244
Change in accrued interest on short-term investments	1,106	912
Amortization of purchased intangible assets	864	759
Gain on the settlement of litigation		(1,400)
Other	525	119
Changes in operating assets and liabilities
Accounts receivable	1,274	(17,686)
Contract assets	7,992	(41,781)
Other assets	(1,588)	(15,895)
Accounts payable and accrued expenses	(12,523)	(44,016)
Contract liabilities	50,072	(37,835)
Net cash provided by (used in) operating activities	15,901	(99,107)
CASH FLOWS FROM INVESTING ACTIVITIES
Maturities of short-term investments	164,000	310,000
Purchases of short-term investments	(75,000)	(158,000)
Purchases of property, plant and equipment	(6,308)	(7,366)
Changes in notes receivable		225
Net cash provided by investing activities	82,692	144,859
CASH FLOWS FROM FINANCING ACTIVITIES
Payments of cash dividends	(11,714)	(11,676)
Proceeds from the exercise of stock options	1,567	48
Distributions to joint venture partners		(72)
Net cash used in financing activities	(10,147)	(11,700)
EFFECTS OF EXCHANGE RATE CHANGES ON CASH	(282)	(368)
NET INCREASE IN CASH AND CASH EQUIVALENTS	88,164	33,684
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	164,318	122,107
CASH AND CASH EQUIVALENTS, END OF PERIOD	252,482	155,791
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for income taxes	3,062	2,625
Cash received from income tax refunds	7,917
Operating lease payments made (Note 7)	466
Cash paid for interest		$ 659
Adoption of ASC Topic 842 (non-cash transaction, see Note 7)	1,341
Right-of-use assets obtained in exchange for new operating lease liabilities (non-cash transaction)	$ 441