Summary of Significant Accounting Policies (Details)	3 Months Ended	12 Months Ended
	Apr. 30, 2018 USD ($)	Jan. 31, 2019 USD ($) Divisions	Jan. 31, 2018 USD ($)	Jan. 31, 2017 USD ($)	Feb. 01, 2019 USD ($)
Basis of Presentation and Principles of Consolidation
Number of divisions operated in by Parent | Divisions		3
Noncontrolling Interest
Payments to noncontrolling Interests		$ 0	$ 0	$ 0
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents, on deposit in the United States		61,221,000	36,434,000
Cash held outside the United States		4,566,000	4,101,000
Equity Investments [Abstract]
Equity Method Investment, Realized Gain (Loss) on Disposal		5,785,000	0	0
Accounts Receivable, Net, Current [Abstract]
Unbilled receivables		1,391,000	2,447,000
Pre-Contract Costs [Abstract]
Pre-contract costs deferred to inventory		0	0
Pre-contract deferred costs written off		0	0	0
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Cumulative Effect of ASU 2018-02 in Period of Adoption		$ 280,000
Impact New Revenue Pronouncement (ASC 606), Effect of change on net income			$ 0	$ 0
Minimum
Intangible Assets
Finite-lived intangible assets, useful life, minimum, years		3 years
Maximum
Intangible Assets
Finite-lived intangible assets, useful life, minimum, years		20 years
Building and Improvements | Minimum
Property, Plant and Equipment [Abstract]
Property, plant and equipment useful lives		15 years
Building and Improvements | Maximum
Property, Plant and Equipment [Abstract]
Property, plant and equipment useful lives		39 years
Machinery and Equipment | Applied Technology | Minimum
Property, Plant and Equipment [Abstract]
Property, plant and equipment useful lives		3 years
Machinery and Equipment | Applied Technology | Maximum
Property, Plant and Equipment [Abstract]
Property, plant and equipment useful lives		5 years
Machinery and Equipment | Engineered Films | Minimum
Property, Plant and Equipment [Abstract]
Property, plant and equipment useful lives		5 years
Machinery and Equipment | Engineered Films | Maximum
Property, Plant and Equipment [Abstract]
Property, plant and equipment useful lives		12 years
Machinery and Equipment | Aerostar | Minimum
Property, Plant and Equipment [Abstract]
Property, plant and equipment useful lives		3 years
Machinery and Equipment | Aerostar | Maximum
Property, Plant and Equipment [Abstract]
Property, plant and equipment useful lives		5 years
Furniture, Fixtures, Office Equipment and Other [Member] | Minimum
Property, Plant and Equipment [Abstract]
Property, plant and equipment useful lives		3 years
Furniture, Fixtures, Office Equipment and Other [Member] | Maximum
Property, Plant and Equipment [Abstract]
Property, plant and equipment useful lives		7 years
Aerostar Integrated Systems [Member]
Noncontrolling Interest
Joint venture, ownership percentage		75.00%
AgEagle Aerial Systems | Applied Technology
Equity Investments [Abstract]
Equity Method Investment, Ownership Percentage			5.00%
Variable Interest Entity, acquisition date equity method investment		2016-02
Variable Interest Entity, name of investee equity method investment		Ag-Eagle Aerial Systems, Inc.
SST | Applied Technology
Equity Investments [Abstract]
Equity Method Investment, Ownership Percentage			22.00%
Variable Interest Entity, name of investee equity method investment			Site-Specific Technology Development Group, Inc.
Proceeds from Sale and Maturity of Other Investments		$ 6,556,000
Hold-back for equity investment sold		15.00%
Other Nonoperating Income (Expense) | SST | Applied Technology
Equity Investments [Abstract]
Equity Method Investment, Realized Gain (Loss) on Disposal	$ 5,785,000	$ 5,785,000
Other Postretirement Benefit Plan, Defined Benefit
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Service cost		28,000	$ 74,000
Interest cost		316,000	$ 312,000
Other Postretirement Benefit Plan, Defined Benefit | Operating Income (Loss)
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Service cost		28,000
Other Postretirement Benefit Plan, Defined Benefit | Other Nonoperating Income (Expense)
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Interest cost		$ 284,000
Scenario, Forecast | Subsequent Event
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Estimated Right-of-Use Asset at adoption of ASU 2016-02					$ 3,900,000
Estimated lease liability at adoption of ASU 2016-02					$ 3,900,000