Revenue from Contracts with Customers - Summary of Disaggregated Revenue by Market and Product (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 746,290	$ 627,041	$ 666,331	$ 340,409	$ 362,728	$ 342,496	$ 342,839	$ 314,433	$ 2,380,071	$ 1,362,496	$ 1,158,794
Unallocated & Other
Disaggregation of Revenue [Line Items]
Revenues									22,051	0
Photonic Solutions | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									1,536,790	638,889	486,485
Compound Semiconductors | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									821,230	723,607	$ 672,309
Commercial | Direct Ship Parts
Disaggregation of Revenue [Line Items]
Revenues									2,154,168	1,194,509
Commercial | Direct Ship Parts | Unallocated & Other
Disaggregation of Revenue [Line Items]
Revenues									22,051	0
Commercial | Services
Disaggregation of Revenue [Line Items]
Revenues									48,215	21,646
Commercial | Services | Unallocated & Other
Disaggregation of Revenue [Line Items]
Revenues									0	0
Commercial | Photonic Solutions | Direct Ship Parts | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									1,524,799	631,407
Commercial | Photonic Solutions | Services | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									11,991	7,482
Commercial | Compound Semiconductors | Direct Ship Parts | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									607,318	563,102
Commercial | Compound Semiconductors | Services | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									36,224	14,164
U.S. Government | Direct Ship Parts
Disaggregation of Revenue [Line Items]
Revenues									158,790	130,313
U.S. Government | Direct Ship Parts | Unallocated & Other
Disaggregation of Revenue [Line Items]
Revenues									0	0
U.S. Government | Services
Disaggregation of Revenue [Line Items]
Revenues									18,898	16,028
U.S. Government | Services | Unallocated & Other
Disaggregation of Revenue [Line Items]
Revenues									0	0
U.S. Government | Photonic Solutions | Direct Ship Parts | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									0	0
U.S. Government | Photonic Solutions | Services | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									0	0
U.S. Government | Compound Semiconductors | Direct Ship Parts | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									158,790	130,313
U.S. Government | Compound Semiconductors | Services | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									$ 18,898	$ 16,028