Long-Term Debt and Notes Payable - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended
	Aug. 02, 2013	Apr. 30, 2015	Apr. 30, 2014	Jan. 31, 2015	Aug. 22, 2014
Line of Credit Facility [Line Items]
Line of credit agreement collateralized by percentage of own capital stock	65.00%
Leverage Ratio		2.00
Fixed charge coverage ratio		1.25
Adjusted EBITDA		$ 22,000,000
Capital expenditures to adjusted EBITDA		1.0
Additional indebtedness		5,000,000
Seamap Pte Ltd [Member]
Line of Credit Facility [Line Items]
Borrowings under the revolving credit facility		3,000,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Borrowings under the revolving credit facility					3,000,000
Carrying value of debt		12,000,000		17,000,000
London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Interest rate of borrowings		3.00%
Credit Agreement [Member]
Line of Credit Facility [Line Items]
Borrowings under the revolving credit facility	50,000,000
Revolving credit facility expiration period	3 years
Credit Agreement [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Commitment fee on the unused portion of the Credit Agreement		0.375%
Credit Agreement [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Commitment fee on the unused portion of the Credit Agreement		0.50%
Available borrowings under the revolving credit facility to secure letters of credit		10,000,000
Credit Agreement [Member] | Predecessor [Member] | Revolving Credit Facility And Seamap Credit Facility [Member]
Line of Credit Facility [Line Items]
Average borrowings under the revolving credit facility		24,400,000	19,000,000
Credit Agreement [Member] | Base Rate [Member]
Line of Credit Facility [Line Items]
Credit Agreement basis points		1.75%
Credit Agreement [Member] | Eurodollar [Member]
Line of Credit Facility [Line Items]
Credit Agreement basis points		2.75%
Seamap Credit Facility [Member]
Line of Credit Facility [Line Items]
Borrowings under the revolving credit facility					15,000,000
Minimum shareholder's equity		15,000,000
Seamap Credit Facility [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Minimum ratio of debt to EBITDA		125.00%
Term Loan [Member]
Line of Credit Facility [Line Items]
Carrying value of debt					10,000,000
Frequency of periodic payments		The term loan portion of the Seamap Credit Facility provides for eleven quarterly principal payments of $800,000 and a final payment of the remaining $1.2 million on or before August 22, 2017.
Maturity period		Aug. 22, 2017
Principal payment of term loan portion		800,000
Final payment of term portion		1,200,000
Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Credit Agreement basis points		2.75%
Singapore Credit Facility Bankers Guarantees [Member]
Line of Credit Facility [Line Items]
Carrying value of debt					$ 2,000,000