Contingencies and Legacy Environmental Commitments - Additional Information (Detail)	1 Months Ended				3 Months Ended					12 Months Ended
	Mar. 31, 2015 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014	Jul. 31, 2001 USD ($)	Jun. 30, 2015 USD ($) Location	Jun. 30, 2014 USD ($)	Jun. 30, 2005	Dec. 31, 2003 USD ($)	Jun. 30, 1999	Mar. 31, 2015 USD ($)
Site Contingency [Line Items]
Aggregate environmental liability	$ 9,255,000				$ 9,195,000					$ 9,255,000
Cost-sharing related to environmental liabilities	1,554,000				1,414,000					1,554,000
Environmental costs					$ 129,000	$ 262,000				946,000
Number of locations for participating in environmental assessments and remediation work | Location					7
Time frame for environmental liabilities					30 years
Real estate held for sale	3,800,000				$ 3,800,000					$ 3,800,000
Glen Head, New York
Site Contingency [Line Items]
Aggregate environmental liability					3,165,000
Real estate held for sale					3,800,000
Sale of environmental remediation property				$ 4,000,000
Additional liquidated amount					750,000
Glen Head, New York | Minimum
Site Contingency [Line Items]
Reduced purchase price	0
Glen Head, New York | Maximum
Site Contingency [Line Items]
Reduced purchase price	$ 1,000,000
Federal Labs
Site Contingency [Line Items]
Aggregate environmental liability					4,122,000
Environmental costs								$ 200,000
Additional environmental remediation expense								$ 200,000
Percentage of environmental costs paid by Federal Government							45.00%		50.00%
Maximum technical and oversight fees					$ 10,000
Decrease in environmental reserve		$ 412,000
Percentage of environmental costs payable			26.00%
Percentage of environmental costs payable thereafter			33.50%
Federal Labs | Minimum
Site Contingency [Line Items]
Time frame for environmental liabilities					20 years
Federal Labs | Maximum
Site Contingency [Line Items]
Time frame for environmental liabilities					30 years
Other Properties
Site Contingency [Line Items]
Aggregate environmental liability					$ 1,908,000