CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
Cash flows from operating activities:
Net income	$ 979,058	$ 1,046,770	$ 682,383
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	40,952	42,257	45,025
Amortization, impairments and write-offs	80,905	30,755	41,485
Stock-based compensation expense	59,317	64,242	48,508
Deferred income tax benefit and other non-cash tax items	(39,450)	44,263	(16,376)
Decrease (increase) in:
Accounts receivable, net	63,702	(59,833)	(26,209)
Inventories, net	162,166	16,404	(74,242)
Other current assets	62,685	(127,287)	67,288
Increase (decrease) in:
Accounts payable	(39,584)	60,562	13,013
Accrued expenses	(6,140)	(102,350)	148,805
Income tax liabilities	84,701	131,738	89,589
Contingent acquisition liabilities	(11,000)
Other	4,915	440	679
Net cash provided by operating activities	1,442,227	1,147,961	1,019,948
Cash flows from investing activities:
Purchase of property, plant and equipment	(80,545)	(38,463)	(32,252)
Purchase of marketable securities	(2,026,247)	(2,942,226)	(2,638,354)
Redemption of marketable securities	2,697,149	2,900,869	2,140,826
Acquisitions	(1,262,651)
Purchase of intangible assets	(469,364)	(289,401)
Net cash used in investing activities	(1,141,658)	(369,221)	(529,780)
Cash flows from financing activities:
Net proceeds from common stock options exercised by employees under stock option plans	9,889	2,896	1,374
Tax benefit (provision) related to stock-based compensation	18	(747)	8,868
Treasury stock transactions	(859,415)	(508,489)	(16,657)
Net cash used in financing activities	(849,508)	(506,340)	(6,415)
Effect of exchange rate changes on cash	(9,384)	1,954	40,826
Increase in cash and cash equivalents	(558,323)	274,354	524,579
Cash and cash equivalents, beginning of year	2,137,838	1,863,484	1,338,905
Cash and cash equivalents, end of year	1,579,515	2,137,838	1,863,484
Supplemental disclosures of cash flow information:
Cash paid for income taxes	$ 190,984	$ 210,834	$ 156,083