Acquisitions - Narrative (Details) - USD ($) $ in Thousands				3 Months Ended	9 Months Ended
	Jan. 29, 2019	Jul. 31, 2018	Feb. 01, 2018	Mar. 31, 2019	Mar. 31, 2019	Jan. 31, 2019	Jul. 18, 2018	Jun. 30, 2018
Business Acquisition [Line Items]
Estimated fair value of goodwill				$ 543,515	$ 543,515			$ 497,442
GECO Avionics, LLC
Business Acquisition [Line Items]
Estimated fair value of goodwill						$ 22,823
Tax deductible goodwill				22,823	22,823
Revenue of acquiree since acquisition date				2,477
Net income (loss) of acquiree since acquisition date				333
Estimated fair value of assets acquired						$ 36,500
GECO Avionics, LLC | Customer Relationships
Business Acquisition [Line Items]
Finite-lived intangible assets acquired	$ 5,500,000
Useful life of acquired assets	11 years
GECO Avionics, LLC | Developed Technology Rights
Business Acquisition [Line Items]
Finite-lived intangible assets acquired	$ 4,800,000
Useful life of acquired assets	10 years
GECO Avionics, LLC | Backlog
Business Acquisition [Line Items]
Finite-lived intangible assets acquired	$ 600,000
Useful life of acquired assets	2 years
Germane Systems
Business Acquisition [Line Items]
Total purchase price		$ 45,000,000			1,244
Estimated fair value of goodwill		$ 23,111
Acquired goodwill, amortization period		15 years
Tax deductible goodwill				22,402	22,402
Revenue of acquiree since acquisition date				12,707	34,756
Net income (loss) of acquiree since acquisition date				$ 1,159	$ 2,065
Estimated fair value of assets acquired		$ 45,922
Germane Systems | Customer Relationships
Business Acquisition [Line Items]
Finite-lived intangible assets acquired		$ 8,500,000
Useful life of acquired assets		11 years
Germane Systems | Developed Technology Rights
Business Acquisition [Line Items]
Finite-lived intangible assets acquired		$ 4,200,000
Useful life of acquired assets		8 years
Germane Systems | Backlog
Business Acquisition [Line Items]
Finite-lived intangible assets acquired		$ 210,000
Useful life of acquired assets		1 year
Themis Computer Acquisition
Business Acquisition [Line Items]
Estimated fair value of goodwill			$ 112,987
Estimated fair value of assets acquired			185,815
Themis Computer Acquisition | Acquisition-related Costs
Business Acquisition [Line Items]
Estimated fair value of assets acquired							$ 700
Themis Computer Acquisition | Customer Relationships
Business Acquisition [Line Items]
Finite-lived intangible assets acquired			$ 52,600
Useful life of acquired assets			12 years 6 months
Themis Computer Acquisition | Developed Technology Rights
Business Acquisition [Line Items]
Finite-lived intangible assets acquired			$ 17,150
Useful life of acquired assets			9 years 6 months
Themis Computer Acquisition | Backlog
Business Acquisition [Line Items]
Finite-lived intangible assets acquired			$ 1,970
Useful life of acquired assets			1 year