Composition of Certain Balance Sheet Captions - Composition of Certain Balance Sheet Captions (Parenthetical) (Detail)	6 Months Ended
	Sep. 30, 2015
Minimum [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Property, equipment and satellites, estimated useful life (years)	2 years
Maximum [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Property, equipment and satellites, estimated useful life (years)	24 years
Satellite - WildBlue-1 [Member] | Property Plant and Equipment - Satellites [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Property, equipment and satellites, estimated useful life (years)	10 years
Capital lease of satellite capacity - Anik F2 [Member] | Property Plant and Equipment - Satellites [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Property, equipment and satellites, estimated useful life (years)	10 years
Satellite - ViaSat-1 [Member] | Property Plant and Equipment - Satellites [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Property, equipment and satellites, estimated useful life (years)	17 years
Equipment and software [Member] | Property Plant and Equipment - Excluding Satellites [Member] | Minimum [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Property, equipment and satellites, estimated useful life (years)	2 years
Equipment and software [Member] | Property Plant and Equipment - Excluding Satellites [Member] | Maximum [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Property, equipment and satellites, estimated useful life (years)	7 years
CPE leased equipment [Member] | Property Plant and Equipment - Excluding Satellites [Member] | Minimum [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Property, equipment and satellites, estimated useful life (years)	4 years
CPE leased equipment [Member] | Property Plant and Equipment - Excluding Satellites [Member] | Maximum [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Property, equipment and satellites, estimated useful life (years)	5 years
Furniture and fixtures [Member] | Property Plant and Equipment - Excluding Satellites [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Property, equipment and satellites, estimated useful life (years)	7 years
Leasehold improvements [Member] | Property Plant and Equipment - Excluding Satellites [Member] | Minimum [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Property, equipment and satellites, estimated useful life (years)	2 years
Leasehold improvements [Member] | Property Plant and Equipment - Excluding Satellites [Member] | Maximum [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Property, equipment and satellites, estimated useful life (years)	17 years
Building [Member] | Property Plant and Equipment - Excluding Satellites [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Property, equipment and satellites, estimated useful life (years)	24 years
Technology [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Other acquired intangible assets, weighted average useful life	6 years
Contracts and customer relationships [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Other acquired intangible assets, weighted average useful life	8 years
Satellite co-location rights [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Other acquired intangible assets, weighted average useful life	9 years
Trade name [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Other acquired intangible assets, weighted average useful life	3 years
Other [Member]
Schedule Of Composition Of Certain Balance Sheet Captions [Line Items]
Other acquired intangible assets, weighted average useful life	7 years