Basis of Presentation - Summary of Impact of Adopting New Standards on Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Disaggregation Of Revenue [Line Items]
Total revenues	$ 438,869	$ 380,044
Selling, general and administrative	112,642	89,173
Independent research and development	33,373	45,065
Loss from operations	(54,479)	(17,950)
Interest expense	(11,324)	(56)
Loss before income taxes	(65,767)	(17,913)
Benefit from income taxes	29,205	9,180
Net loss	(35,497)	(9,246)
Net loss attributable to Viasat, Inc.	$ (34,010)	$ (9,039)
Basic net loss per share attributable to Viasat, Inc. common stockholders	$ (0.57)	$ (0.16)
Diluted net loss per share attributable to Viasat, Inc. common stockholders	$ (0.57)	$ (0.16)
Impact of ASC 606 [Member] | ASC 606 [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	$ (487)
Selling, general and administrative	2,338
Independent research and development	2,745
Loss from operations	(5,698)
Interest expense	992
Loss before income taxes	(4,706)
Benefit from income taxes	(185)
Net loss	(4,891)
Net loss attributable to Viasat, Inc.	$ (4,891)
Basic net loss per share attributable to Viasat, Inc. common stockholders	$ (0.08)
Diluted net loss per share attributable to Viasat, Inc. common stockholders	$ (0.08)
Historical Accounting Method [Member] | ASC 606 [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	$ 438,382
Selling, general and administrative	114,980
Independent research and development	36,118
Loss from operations	(60,177)
Interest expense	(10,332)
Loss before income taxes	(70,473)
Benefit from income taxes	29,020
Net loss	(40,388)
Net loss attributable to Viasat, Inc.	$ (38,901)
Basic net loss per share attributable to Viasat, Inc. common stockholders	$ (0.66)
Diluted net loss per share attributable to Viasat, Inc. common stockholders	$ (0.66)
Product [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	$ 218,129	$ 166,118
Cost of revenues	173,448	122,645
Product [Member] | Impact of ASC 606 [Member] | ASC 606 [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	579
Cost of revenues	249
Product [Member] | Historical Accounting Method [Member] | ASC 606 [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	218,708
Cost of revenues	173,697
Service [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	220,740	213,926
Cost of revenues	171,432	$ 137,851
Service [Member] | Impact of ASC 606 [Member] | ASC 606 [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	(1,066)
Cost of revenues	(121)
Service [Member] | Historical Accounting Method [Member] | ASC 606 [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	219,674
Cost of revenues	$ 171,311