CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		12 Months Ended
		Mar. 31, 2020	Mar. 31, 2019		Mar. 31, 2018
Operating activities:
Net income		$ 404,459	$ 333,837	[1]	$ 173,533	[1]
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization and impairment of software development costs and licenses		167,925	201,221	[1]	77,887	[1]
Stock-based compensation		257,881	247,700	[1]	116,349	[1]
Amortization of intellectual property		20,990	23,879	[1]	34,830	[1]
Depreciation		47,628	39,726	[1]	32,202	[1]
Amortization of discount on Convertible Notes		0	91	[1]	15,662	[1]
Impairment of in-process research and development		0	0	[1]	11,257	[1]
Deferred income taxes		(3,486)	110,603	[1]	(32,523)	[1]
Impairment of long-term investments		5,333	0		0
Gain on redemption of Convertible Notes		0	0	[1]	(4,900)	[1]
Other, net		3,741	584	[1]	6,953	[1]
Changes in assets and liabilities:
Accounts receivable		(195,484)	(98,075)	[1]	(26,998)	[1]
Inventory		8,489	(14,403)	[1]	3,917	[1]
Software development costs and licenses		(48,434)	(206,831)	[1]	(225,269)	[1]
Prepaid expenses, other current and other non-current assets		(259,817)	(275,800)	[1]	(74,544)	[1]
Deferred revenue		(55,460)	304,713	[1]	198,397	[1]
Deferred cost of goods sold		32,180	(24,882)	[1]	(11,959)	[1]
Accounts payable, accrued expenses and other liabilities		299,733	201,152	[1]	198,733	[1]
Net cash provided by operating activities		685,678	843,515	[1]	493,527	[1]
Investing activities:
Change in bank time deposits		196,720	(171,057)	[1]	(40,918)	[1]
Proceeds from available-for-sale securities		400,635	325,133	[1]	241,012	[1]
Purchases of available-for-sale securities		(499,991)	(282,534)	[1]	(369,998)	[1]
Purchases of fixed assets		(53,384)	(66,969)	[1]	(61,557)	[1]
Purchase of long-term investments		(27,891)	0	[1]	(5,000)	[1]
Business acquisitions, net of cash acquired		(12,040)	(28,149)	[1]	(9,401)	[1]
Asset acquisition		0	0	[1]	(25,965)	[1]
Net cash provided by (used in) investing activities		4,049	(223,576)	[1]	(271,827)	[1]
Financing activities:
Tax payment related to net share settlements on restricted stock awards		(87,968)	(101,293)	[1]	(112,884)	[1]
Repurchase of common stock		0	(362,392)	[1]	(154,792)	[1]
Issuance of common stock		10,515	0	[1]	0	[1]
Other		0	0	[1]	(13,791)	[1]
Net cash used in financing activities		(77,453)	(463,685)	[1]	(281,467)	[1]
Effects of foreign currency exchange rates on cash, cash equivalents, and restricted cash and cash equivalents		(10,868)	(10,639)	[1]	24,924	[1]
Net change in cash, cash equivalents, and restricted cash and cash equivalents		601,406	145,615	[1]	(34,843)	[1]
Cash, cash equivalents, and restricted cash and cash equivalents, beginning of year	[1]	1,391,986	1,246,371		1,281,214
Cash, cash equivalents, and restricted cash equivalents, end of year		1,993,392	1,391,986	[1]	1,246,371	[1]
Supplemental data:
Interest paid		4,750	5,265	[1]	4,121	[1]
Income taxes paid		$ 27,998	$ 19,280	[1]	$ 8,790	[1]

[1] Prior period amounts have been adjusted retrospectively to reflect the adoption of ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. Refer to Note 1 for further discussion.