CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net income (loss)	$ (32,103)	$ 979,058	$ 1,046,770
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	47,270	40,952	42,257
Amortization, impairments and write-offs	99,999	80,905	30,755
Stock-based compensation expense	64,725	59,317	64,242
Deferred income tax benefit and other non-cash tax items	(26,752)	(39,450)	44,263
Decrease (increase) in:
Accounts receivable, net	(6,248)	63,702	(59,833)
Inventories, net	(95,783)	162,166	16,404
Other current assets	8,247	62,685	(127,287)
Increase (decrease) in:
Accounts payable	3,074	(39,584)	60,562
Accrued expenses	94,831	(6,140)	(102,350)
Income tax liabilities	(3,106)	84,701	131,738
Contingent acquisition and other liabilities	(18,662)	(11,000)
Other	(378)	4,915	440
Net cash provided by operating activities	135,114	1,442,227	1,147,961
Cash flows from investing activities:
Purchase of property, plant and equipment	(64,384)	(80,545)	(38,463)
Purchase of marketable securities	(3,476,059)	(2,026,247)	(2,942,226)
Redemption of marketable securities	2,968,734	2,697,149	2,900,869
Acquisitions		(1,262,651)
Purchase of intangible assets	(125,000)	(469,364)	(289,401)
Other investing activities	(108,077)
Net cash used in investing activities	(804,786)	(1,141,658)	(369,221)
Cash flows from financing activities:
Net proceeds from common stock options exercised by employees under stock option plans	31,969	9,889	2,896
Tax benefit (provision) related to stock-based compensation	1,807	18	(747)
Treasury stock transactions	(11,010)	(859,415)	(508,489)
Net cash provided by (used in) financing activities	22,766	(849,508)	(506,340)
Effect of exchange rate changes on cash	3,066	(9,384)	1,954
(Decrease) increase in cash and cash equivalents	(643,840)	(558,323)	274,354
Cash and cash equivalents, beginning of year	1,579,515	2,137,838	1,863,484
Cash and cash equivalents, end of year	935,675	1,579,515	2,137,838
Supplemental disclosures of cash flow information:
Cash paid for income taxes	$ 64,267	$ 190,984	$ 210,834