Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended
	Dec. 31, 2009	Dec. 31, 2010 Restated [Member]
Cash flows from operating activities:
Net (loss) income	$ 11,311	$ (1,150)
Adjustments to reconcile net (loss) income to net cash used in operations:
Depreciation and amortization	7,158	7,990
Stock-based compensation expense	10,440	10,073
Stock-based compensation expense-non-employee	91	238
Provision for excess and obsolete inventory		2,667
Allowance for doubtful accounts	260	25
Write-off of prepaid value added taxes		550
Deferred income taxes	(1,608)	(3,902)
Other non-cash items	745	2,025
Changes in operating asset and liability accounts:
Accounts receivable	(27,495)	40,431
Inventory	(728)	(42,934)
Prepaid expenses and other current assets	(8,518)	(16,973)
Accounts payable and accrued expenses	3,325	4,945
Deferred revenue	3,882	(20,027)
Net cash used in operating activities	(1,137)	(16,042)
Cash flows from investing activities:
Purchase of property, plant and equipment	(8,232)	(30,689)
Purchase of marketable securities	(68,096)	(71,763)
Proceeds from the maturity of marketable securities	40,638	47,462
Change in restricted cash	1,645	250
Purchase of intangible assets	(1,360)	(2,001)
Purchase of minority investment	(848)	(8,000)
Change in other assets	(31)	(30)
Net cash used in investing activities	(36,284)	(64,771)
Cash flows from financing activities:
Proceeds from public equity offering, net		155,240
Proceeds from exercise of employee stock options and ESPP	6,048	7,350
Net cash provided by financing activities	6,048	162,590
Effect of exchange rate changes on cash and cash equivalents	1,082	(351)
Net (decrease) increase in cash and cash equivalents	(30,291)	81,427
Cash and cash equivalents at end of period	40,383	169,021
Supplemental schedule of cash flow information:
Non-cash contingent consideration in connection with acquisitions	10,828	10,004
Cash paid for income taxes	5,870	13,660
Non-cash issuance of common stock	$ 1,610	$ 637