CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	6 Months Ended
	Jul. 31, 2015	Jul. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 26,685,000	$ 16,821,000
Adjustments to reconcile net income to net cash (used in) provided by operating activities
Stock option compensation expense	1,057,000	968,000
Depreciation	258,000	283,000
Amortization of purchased intangibles	164,000	121,000
Deferred income tax expense (benefit)	185,000	(125,000)
Gain on the deconsolidation of a variable interest entity	(264,000)
Changes in operating assets and liabilities
Accounts receivable	(5,774,000)	(10,766,000)
Costs and estimated earnings in excess of billings	945,000	97,000
Prepaid expenses and other assets	(1,133,000)	(1,098,000)
Accounts payable and accrued expenses	(3,739,000)	17,407,000
Billings in excess of costs and estimated earnings	(46,977,000)	46,848,000
Net cash (used in) provided by operating activities	(28,593,000)	70,556,000
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of short-term investments, net	(117,000,000)
Purchase of APC, net of cash acquired (Note 2)	(4,210,000)
Purchases of property, plant and equipment	(2,503,000)	(199,000)
Loans to energy project developers	(605,000)	(320,000)
Net cash used in investing activities	(124,318,000)	(519,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the exercise of stock options	1,000,000	2,282,000
Excess income tax benefit on exercised stock options	356,000	630,000
Net cash provided by financing activities	1,356,000	2,912,000
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(151,555,000)	72,949,000
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	333,691,000	272,209,000
CASH AND CASH EQUIVALENTS, END OF PERIOD	182,136,000	345,158,000
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for income taxes	$ 10,703,000	$ 5,153,000