CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 51,869	$ 72,346	$ 77,426
Adjustments to reconcile net income to net cash (used in) provided by operating activities
Depreciation	3,422	2,779	2,043
Stock compensation expense	1,645	4,651	2,344
Impairment losses	1,491	584	1,979
Amortization of purchased intangible assets	1,012	1,032	1,163
Change in accrued interest on short-term investments	695	(1,112)	(698)
Deferred income tax (benefit) expense	(2,139)	(64)	1,237
Other (Note 11)	(996)	(136)	1,215
Changes in operating assets and liabilities
Accounts receivable	(10,200)	(5,687)	817
Other assets	(15,160)	(4,574)	(668)
Accounts payable and accrued expenses	(60,187)	(6,164)	59,522
Changes in contracts-in-progress, net (Note 4)	(83,774)	(136,448)	112,664
Net cash (used in) provided by operating activities	(112,322)	(72,793)	259,044
CASH FLOWS FROM INVESTING ACTIVITIES
Maturities of short-term investments	370,000	587,500	354,000
Purchases of short-term investments	(191,000)	(542,500)	(595,000)
Purchases of property, plant and equipment	(8,599)	(4,826)	(2,811)
Changes in notes receivable	225	(1,500)
Net cash provided by (used in) investing activities	170,626	38,674	(243,811)
CASH FLOWS FROM FINANCING ACTIVITIES
Cash dividends paid	(15,570)	(15,548)	(15,260)
Proceeds from the exercise of stock options	102	3,155	15,901
Distributions to joint venture partners	(72)	(1,229)	(9,500)
Net cash used in financing activities	(15,540)	(13,622)	(8,859)
EFFECTS OF EXCHANGE RATE CHANGES ON CASH	(553)	2,650	(85)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	42,211	(45,091)	6,289
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR	122,107	167,198	160,909
CASH AND CASH EQUIVALENTS, END OF YEAR	164,318	122,107	167,198
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for income taxes	3,900	$ 44,309	$ 36,861
Cash paid for interest (Note 11)	$ 659