Financing Arrangements - Additional Information (Detail) (USD $)	3 Months Ended
	Apr. 30, 2015	Jan. 31, 2015
Debt Instrument [Line Items]
Borrowing available under financing arrangements	$ 4,250,000
Interest rate on borrowings under the line of credit	LIBOR plus 2.25%
Interest rate margin on referred rate	2.25%
Borrowing amount to designated to cover letters of credit issued by Bank in support of project development activities	1,350,000
Maximum amount of other standby letters of credits that may be outstanding	10,000,000
Borrowings outstanding under Bank financing arrangements	$ 0	$ 0
Expiration date of financing arrangements	Jul. 31, 2015
Minimum [Member]
Debt Instrument [Line Items]
Expiration date of letters of credit	Sep. 23, 2015
Maximum [Member]
Debt Instrument [Line Items]
Expiration date of letters of credit	Nov. 05, 2015