Summary of Performance of Operations by Reportable Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting, Revenue Reconciling Item [Line Items]
Intersegment revenues	$ 0	$ 0	$ 0	$ 0
Net revenues	55,500	54,123	162,530	153,355
Adjusted EBITDA	7,663	5,242	16,374	7,888
Reportable Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues to unaffiliated customers	55,500	54,123	162,530	153,355
Net revenues	55,500	54,123	162,530	153,355
Adjusted EBITDA	7,663	5,242	16,374	7,888
MCE | Reportable Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues to unaffiliated customers	43,041	41,222	128,835	110,369
Intersegment revenues	4,568	2,733	8,415	10,880
Net revenues	47,609	43,955	137,250	121,249
Adjusted EBITDA	6,763	3,320	13,188	797
Mercury Defense and Intelligence Systems | Reportable Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues to unaffiliated customers	10,991	13,006	32,724	42,899
Intersegment revenues		0	0	12
Net revenues	10,991	13,006	32,724	42,911
Adjusted EBITDA	1,132	1,885	3,411	7,080
Eliminations | Reportable Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues to unaffiliated customers	1,468	(105)	971	87
Intersegment revenues	(4,568)	(2,733)	(8,415)	(10,892)
Net revenues	(3,100)	(2,838)	(7,444)	(10,805)
Adjusted EBITDA	$ (232)	$ 37	$ (225)	$ 11