Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net (loss) income	$ (66,469)	$ (68,275)	$ 21,767
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation	262,289	210,441	200,686
Amortization of intangible assets	56,324	45,211	45,236
Deferred income taxes	(43,813)	(36,558)	(218)
Stock-based compensation expense	79,599	68,545	55,775
Loss on disposition of fixed assets	41,957	32,978	35,431
Loss on extinguishment of debt		10,217
Other non-cash adjustments	18,483	6,883	10,018
Increase (decrease) in cash resulting from changes in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable	(46,108)	(12,439)	16,071
Inventories	(36,593)	(37,562)	(12,386)
Other assets	(2,349)	(25,975)	(15,259)
Accounts payable	(5,714)	32,503	972
Accrued liabilities	71,478	60,042	48,039
Other liabilities	(1,533)	72,622	5,166
Net cash provided by operating activities	327,551	358,633	411,298
Cash flows from investing activities:
Purchase of property, equipment and satellites	(636,855)	(511,634)	(514,692)
Cash paid for patents, licenses and other assets	(49,965)	(72,853)	(70,966)
Proceeds from insurance claims on ViaSat-2 satellite	185,706
Payments related to acquisition of businesses, net of cash acquired	(2,339)		(16,528)
Proceeds from sale of real property	14,034		27,559
Investment in unconsolidated affiliate			(140,378)
Net cash used in investing activities	(489,419)	(584,487)	(715,005)
Cash flows from financing activities:
Proceeds from issuance of Notes	600,000	700,000
Payment of debt issuance costs	(9,767)	(9,759)	(6,677)
Proceeds from issuance of common stock under equity plans	26,330	26,165	22,403
Purchase of common stock in treasury (immediately retired) related to tax withholdings for stock-based compensation	(28,826)	(24,206)	(21,670)
Proceeds from common stock issued in public offering, net of issuance costs			503,061
Proceeds from noncontrolling interest capital contribution		8,491
Other financing activities	(10,280)	(1,816)	(1,802)
Net cash provided by financing activities	354,617	165,776	392,784
Effect of exchange rate changes on cash	(2,494)	1,426	(1,067)
Net increase (decrease) in cash and cash equivalents	190,255	(58,652)	88,010
Cash and cash equivalents at beginning of fiscal year	71,446	130,098	42,088
Cash and cash equivalents at end of fiscal year	261,701	71,446	130,098
Supplemental information:
Cash paid for interest (net of amounts capitalized)	35,119	3,722	10,094
Cash paid for income taxes, net	1,758	4,021	1,468
Non-cash investing and financing activities:
Issuance of common stock in satisfaction of certain accrued employee compensation liabilities	32,129	16,409	13,080
Capital expenditures not paid for	40,619	41,149	29,813
Debt issuance costs not paid for	2,479
Issuance of common stock in connection with acquisition			4,988
2020 Notes [Member]
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Loss on extinguishment of debt		10,217
Cash flows from financing activities:
Repayment of 2020 Notes		(575,000)
Payment of debt extinguishment costs		(10,602)
Revolving Credit Facility [Member]
Cash flows from financing activities:
Proceeds from credit facility borrowings	510,000		90,000
Payments of credit facility borrowings	(510,000)		(270,000)
Ex-Im Credit Facility [Member]
Cash flows from financing activities:
Proceeds from credit facility borrowings		52,503	77,469
Payments of credit facility borrowings	$ (222,840)
Non-cash investing and financing activities:
Exposure fees on Ex-Im credit facility financed through Ex-Im credit facility		$ 5,764	$ 8,505