Segment Reporting (Schedule Of Financial Information Of Company's Operations By Segment) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Jun. 30, 2012
Schedule Of Identifiable Assets By Segment [Line Items]
Revenues	$ 132,292	$ 138,373
Segment earnings	16,594	23,035
Interest expense	(36)	(59)
Other income, net	761	1,630
Income taxes	(4,187)	(5,892)
Net earnings	13,132	18,714
Depreciation and amortization	9,072	8,310
Segment assets	711,125	665,928	706,486
Expenditures for property, plant and equipment	5,929	12,712
Equity investment	11,026	15,777	10,700
Goodwill	80,748	85,833	80,748
Infrared Optics [Member]
Schedule Of Identifiable Assets By Segment [Line Items]
Revenues	51,556	50,796
Inter-segment revenues	500	658
Segment earnings	11,842	12,357
Depreciation and amortization	2,064	2,195
Segment assets	225,857	201,558
Expenditures for property, plant and equipment	1,376	1,700
Goodwill	9,695	9,834
Near-Infrared Optics [Member]
Schedule Of Identifiable Assets By Segment [Line Items]
Revenues	40,646	30,989
Inter-segment revenues	332	542
Segment earnings	7,722	2,560
Depreciation and amortization	4,287	3,643
Segment assets	273,585	236,405
Expenditures for property, plant and equipment	1,409	4,215
Goodwill	48,413	53,359
Military & Materials [Member]
Schedule Of Identifiable Assets By Segment [Line Items]
Revenues	23,935	30,780
Inter-segment revenues	1,540	1,936
Segment earnings	(2,148)	2,110
Depreciation and amortization	1,487	1,535
Segment assets	106,658	126,498
Expenditures for property, plant and equipment	1,330	3,513
Goodwill	12,326	12,326
Advanced Products Group [Member]
Schedule Of Identifiable Assets By Segment [Line Items]
Revenues	16,155	25,808
Inter-segment revenues	1,184	784
Segment earnings	(822)	6,008
Depreciation and amortization	1,234	937
Segment assets	105,025	101,467
Expenditures for property, plant and equipment	1,814	3,284
Equity investment	11,026	15,777
Goodwill	10,314	10,314
Eliminations
Schedule Of Identifiable Assets By Segment [Line Items]
Inter-segment revenues	$ (3,556)	$ (3,920)