Segment Information - Segment Revenues and Operating Profits (Losses) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Revenues:
Product revenues	$ 160,676	$ 168,348
Service revenues	202,454	176,030
Total revenues	363,130	344,378
Operating profits (losses):
Income from operations	7,778	9,414
Amortization of acquired intangible assets	(2,513)	(4,810)
Operating Segments [Member]
Operating profits (losses):
Income from operations	10,291	14,224
Operating Segments [Member] | Satellite Services [Member]
Revenues:
Product revenues	6,685	6,276
Service revenues	145,708	126,140
Total revenues	152,393	132,416
Operating profits (losses):
Income from operations	30,867	17,041
Amortization of acquired intangible assets	(1,104)	(2,765)
Operating Segments [Member] | Commercial Networks [Member]
Revenues:
Product revenues	58,596	61,511
Service revenues	6,957	5,244
Total revenues	65,553	66,755
Operating profits (losses):
Income from operations	(38,531)	(18,733)
Amortization of acquired intangible assets	(445)	(496)
Operating Segments [Member] | Government Systems [Member]
Revenues:
Product revenues	95,395	100,561
Service revenues	49,789	44,646
Total revenues	145,184	145,207
Operating profits (losses):
Income from operations	17,955	15,916
Amortization of acquired intangible assets	(964)	(1,549)
Material Reconciling Items [Member]
Operating profits (losses):
Amortization of acquired intangible assets	$ (2,513)	$ (4,810)