Segment Information - Segment Revenues and Operating Profits (Losses) (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Product revenues	$ 166,118	$ 160,676
Income (loss) from operations	(17,950)	7,778
Operating Segments [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations	(14,690)	10,291
Operating Segments [Member] | Satellite Services [Member]
Segment Reporting Information [Line Items]
Product revenues	217	6,685
Income (loss) from operations	$ 18,843	30,867
Operating Segments [Member] | Implied License [Member] | Satellite Services [Member]
Segment Reporting Information [Line Items]
Product revenues		6,600
Income (loss) from operations		$ 6,600