Segment Information - Segment Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Mar. 31, 2016	Apr. 03, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 2,954,653	$ 2,397,312	$ 2,147,405
Operating Segments [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	587,962	582,399	554,371
Operating Segments [Member] | Satellite Services [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	81,728	57,529	63,790
Operating Segments [Member] | Commercial Networks [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	179,992	212,943	217,268
Operating Segments [Member] | Government Systems [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	326,242	311,927	273,313
Corporate, Non-Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 2,366,691	$ 1,814,913	$ 1,593,034