Summary of Performance of Operations by Reportable Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	$ 54,123	$ 66,989	$ 153,355	$ 184,070
Adjusted EBITDA	5,242	12,007	7,888	39,572
Reportable Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues to unaffiliated customers	54,123	66,989	153,355	184,070
Net revenues	54,123	66,989	153,355	184,070
Adjusted EBITDA	5,242	12,007	7,888	39,572
Mercury Commercial Electronics | Reportable Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues to unaffiliated customers	41,222	49,980	110,369	159,438
Intersegment revenues	2,733	4,205	10,880	8,134
Net revenues	43,955	54,185	121,249	167,572
Adjusted EBITDA	3,320	8,499	797	34,650
Mercury Defense and Intelligence Systems | Reportable Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues to unaffiliated customers	13,006	15,265	42,899	24,628
Intersegment revenues			12
Net revenues	13,006	15,265	42,911	24,628
Adjusted EBITDA	1,885	3,118	7,080	4,791
Eliminations | Reportable Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues to unaffiliated customers	(105)	1,744	87	4
Intersegment revenues	(2,733)	(4,205)	(10,892)	(8,134)
Net revenues	(2,838)	(2,461)	(10,805)	(8,130)
Adjusted EBITDA	$ 37	$ 390	$ 11	$ 131