The Company and a Summary of Its Significant Accounting Policies - Additional Information (Detail 2) - USD ($)	3 Months Ended		12 Months Ended
	Dec. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2024
Company And Summary Of Significant Accounting Policies [Line Items]
Capitalized interest expense			$ 240,700,000	$ 215,400,000	$ 227,500,000
Insurance recovery proceeds			10,000,000	251,500,000	508,560,000
Capitalized costs, net, related to software developed for resale		$ 780,300,000	871,100,000	780,300,000
Gross capitalized implementation costs incurred in cloud computing arrangements		88,700,000	112,200,000	88,700,000
Accumulated amortization related to capitalized software developed for resale		515,800,000	554,200,000	515,800,000
Accumulated amortization related to capitalized implementation costs incurred in cloud computing arrangements		18,400,000	29,000,000	18,400,000
Total capitalized costs related to patents, orbital slots and other licenses		129,400,000	144,500,000	129,400,000
Accumulated amortization of patents, orbital slots and other licenses		10,200,000	24,300,000	10,200,000
Patents, orbital slots and other licenses amortization expense			14,100,000
Debt issuance costs capitalized			5,100,000	35,600,000	53,900,000
Capitalized cost related to software development for resale			95,700,000	78,400,000
Amortization expense of capitalized software development costs	$ 41,100,000			54,500,000	59,100,000
Amortization of capitalized implementation costs incurred in cloud computing arrangements			10,500,000	8,800,000	4,200,000
Goodwill and other intangible assets impairment			0	0	0
Self-insurance liability		5,900,000	$ 5,600,000	5,900,000
Revenue, practical expedient, financing component			true
Revenue, practical expedient, incremental cost of obtaining contract [true false]			true
Asset Impairment			$ 0	0	$ 0
Software Development Costs [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
2027			58,800,000
2028			74,000,000
2029			63,100,000
2030			45,100,000
2031			$ 27,400,000
Minimum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			2 years
Estimated useful life, years			2 years
Maximum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			38 years
Estimated useful life, years			12 years
Maximum [Member] | Software Development Costs [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life, years			5 years
Internally Developed Software [Member] | Minimum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			3 years
Internally Developed Software [Member] | Maximum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			7 years
CPE Leased Equipment [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites		525,972,000	$ 522,882,000	525,972,000
Accumulated depreciation and amortization		328,000,000	$ 349,400,000	328,000,000
CPE Leased Equipment [Member] | Minimum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			3 years
CPE Leased Equipment [Member] | Maximum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			7 years
ViaSat-3 F1 satellite [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Maximum expected recovery % of the planned throughput					10.00%
Satellites [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Reduction to carrying value including capitalized interest					$ 1,670,000,000
Insurance claim receivables					770,000,000
Insurance recovery proceeds			$ 10,000,000	$ 251,500,000	508,600,000
Impairment charges and other liabilities		$ 169,400,000
Satellites [Member] | Selling General and Administrative Expenses [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Satellite impairment loss, net, including liabilities associated with the termination of certain subcontractor agreements					$ 905,500,000
Satellites [Member] | Minimum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			7 years
Satellites [Member] | Maximum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			17 years