Goodwill and Acquired Intangible Assets - Allocation of Other Acquired Intangible Assets and Related Accumulated Amortization (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Other acquired intangible assets, gross	$ 213,281	$ 217,784
Other acquired intangible assets, accumulated amortization	(198,842)	(195,483)
Other acquired intangible assets, net	$ 14,439	22,301
Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life	6 years
Other acquired intangible assets, gross	$ 89,228	89,972
Other acquired intangible assets, accumulated amortization	(78,935)	(73,992)
Other acquired intangible assets, net	$ 10,293	15,980
Contracts and Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life	7 years
Other acquired intangible assets, gross	$ 103,114	103,283
Other acquired intangible assets, accumulated amortization	(98,968)	(96,970)
Other acquired intangible assets, net	$ 4,146	6,313
Satellite Co-Location Rights [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life	9 years
Other acquired intangible assets, gross	$ 8,600	8,600
Other acquired intangible assets, accumulated amortization	$ (8,600)	(8,592)
Other acquired intangible assets, net		8
Trade Name [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life	3 years
Other acquired intangible assets, gross	$ 5,940	5,940
Other acquired intangible assets, accumulated amortization	$ (5,940)	(5,940)
Other [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life	8 years
Other acquired intangible assets, gross	$ 6,399	9,989
Other acquired intangible assets, accumulated amortization	$ (6,399)	$ (9,989)