CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 27,731	$ 256,570
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	340,925	207,662
Deferred income taxes	(52,215)	(11,116)
Share-based compensation expense related to equity incentive plans	106,089	54,103
Excess tax benefit from share-based compensation	0	(735)
Amortization of debt discount on convertible debentures	36,907	35,909
Amortization of debt issuance costs	3,182	2,916
Losses on equity method investments	167	289
Gains on sale of assets	(78)	(960)
Losses on write-down of fixed assets	1,278	0
Impairment of intangible assets	10,226	577
Realized losses (gains) on available-for-sale investment	89	(14,054)
Realized gains on equity method investment	(468)	(2,225)
Impairment of available-for-sale investment	1,433	3,995
Amortization of premium on available-for-sale investments	5	7,230
Special charges (income) and other, net	850	1,351
Changes in operating assets and liabilities, excluding impact of acquisitions:
(Increase) decrease in accounts receivable	(43,551)	40,027
Decrease in inventories	220,674	34,773
Increase (decrease) in deferred income on shipments to distributors	110,827	(2,888)
Decrease in accounts payable and accrued liabilities	(22,261)	(44,434)
Change in other assets and liabilities	(14,266)	(27,099)
Operating cash flows related to discontinued operations	9,348	0
Net cash provided by operating activities	736,892	541,891
Cash flows from investing activities:
Purchases of available-for-sale investments	(35,147)	(1,542,864)
Sales and maturities of available-for-sale investments	470,565	1,193,487
Sale of equity method investment	468	2,667
Acquisition of Atmel, net of cash acquired	(2,747,516)	0
Acquisition of Micrel, net of cash acquired	0	(343,928)
Purchase of additional controlling interest in ISSC	0	(18,051)
Investments in other assets	(9,597)	(5,961)
Proceeds from sale of assets	23,069	14,296
Capital expenditures	(52,338)	(81,423)
Net cash used in investing activities	(2,350,496)	(781,777)
Cash flows from financing activities:
Repayments of revolving loan under credit facility	(1,078,500)	(571,000)
Proceeds from borrowings on revolving loan under credit facility	1,517,000	1,117,500
Deferred financing costs	0	(2,156)
Payment of cash dividends	(232,847)	(217,939)
Repurchase of common stock	0	(363,829)
Proceeds from sale of common stock	28,893	17,916
Tax payments related to shares withheld for vested restricted stock units	(48,161)	(17,201)
Capital lease payments	(587)	(504)
Excess tax benefit from share-based compensation	0	735
Net cash provided by (used in) financing activities	185,798	(36,478)
Effect of foreign exchange rate changes on cash and cash equivalents	(1,007)	0
Net decrease in cash and cash equivalents	(1,428,813)	(276,364)
Cash and cash equivalents at beginning of period	2,092,751	607,815
Cash and cash equivalents at end of period	$ 663,938	$ 331,451