Contingencies and Legacy Environmental Commitments - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended		1 Months Ended			3 Months Ended				3 Months Ended
	Jun. 30, 2013 Location	Jun. 30, 2012	Mar. 31, 2013	Jun. 30, 2013 Other Properties [Member]	Jul. 31, 2001 Glen Head, New York [Member]	Jun. 30, 2013 Glen Head, New York [Member]	Dec. 31, 2005 Glen Head, New York [Member]	Jun. 30, 2005 Federal Labs [Member]	Dec. 31, 2003 Federal Labs [Member]	Jun. 30, 1999 Federal Labs [Member]	Jun. 30, 2013 Federal Labs [Member]	Jun. 30, 2013 Federal Labs [Member] Minimum [Member]	Jun. 30, 2013 Federal Labs [Member] Maximum [Member]	Jun. 30, 2013 Illinois Environmental Protection Agency [Member]
Site Contingency [Line Items]
Aggregate environmental liability	$ 11,243		$ 12,684	$ 2,628		$ 3,211					$ 5,404
Cost-sharing related to environmental liabilities	1,472		1,472
Environmental costs	324	239	1,245						200
Number of locations for participating in environmental assessments and remediation work	10
Time frame for environmental liabilities	30 years											20 years	30 years
Property "held for sale"						3,800
Sale of environmental remediation property					4,000
Appraised value of property					3,300		4,200
Additional environmental remediation expense									200
Percentage of environmental costs paid by Federal Government								45.00%		50.00%
Maximum technical and oversight fees														35
Reduction in remaining environmental liability	$ 1,207