CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) shares in Thousands, $ in Thousands	9 Months Ended
	Oct. 31, 2016	Oct. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 56,645	$ 41,044
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Impairment loss	1,979
Stock option compensation expense	1,774	1,708
Depreciation	1,444	444
Amortization of purchased intangibles	752	283
Deferred income tax (benefit) expense	(1,693)	988
Gain on the deconsolidation of a variable interest entity		(349)
Other	(119)
Changes in operating assets and liabilities
Accounts receivable	21,304	(8,072)
Prepaid expenses and other assets	(1,432)	(1,525)
Accounts payable and accrued expenses	50,099	(4,702)
Billings in excess of costs and estimated earnings, net	54,558	(76,207)
Net cash provided by (used in) operating activities	185,311	(46,388)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of short-term investments	(375,000)	(168,000)
Maturities of short-term investments	214,000	64,000
Purchases of property, plant and equipment, net	(2,481)	(2,671)
Purchase of APC, net of cash acquired		(4,210)
Increase in notes receivable		(931)
Net cash used in investing activities	(163,481)	(111,812)
CASH FLOWS FROM FINANCING ACTIVITIES
Cash dividends paid	(15,260)
Distributions to joint venture partners	(7,500)
Proceeds from the exercise of stock options	10,988	1,670
Excess income tax benefit on exercised stock options (Note 2)		88
Net cash (used in) provided by financing activities	(11,772)	1,758
EFFECTS OF EXCHANGE RATE CHANGES ON CASH	(192)	(411)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	9,866	(156,853)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	160,909	333,691
CASH AND CASH EQUIVALENTS, END OF PERIOD	170,775	176,838
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for income taxes	$ 26,364	$ 20,734
Common stock issued in connection with the acquisition of APC (noncash transaction, see Note 3)		3,536
Cash dividends declared in September 2015, paid in November 2015 (noncash transaction, see Note 14)		$ 10,378