Income taxes (Tables)

12 Months Ended

Mar. 31, 2011

Notes to Financial Statements [Abstract]

Rollforward of unrecognized tax benefits

The following table summarizes the activity related to the Company's gross unrecognized tax benefits from April 1, 2008 to March 31, 2011 (amounts in thousands):

	Year Ended March 31,
	2011			2010			2009
Beginning balance	$	57,140		$	70,051		$	112,311
Increases related to acquisitions		26,843			---			---
Decreases related to prior year tax positions		(48,428	)		(25,492	)		(49,967	)
Increases related to current year tax positions		9,977			11,332			7,584
Increases related to prior year tax positions		379			1,249			123
Ending balance	$	45,911		$	57,140		$	70,051

Components of income tax expense (benefit)

The income tax (benefit) provision from continuing operations consists of the following (amounts in thousands):

	Year Ended March 31,
	2011			2010			2009
Current (benefit) expense:
Federal	$	294		$	(4,358	)	$	(38,836	)
State		21			(436	)		(3,888	)
Foreign		22,877			6,981			8,689
Total current	$	23,192			2,187			(34,035	)
Deferred expense (benefit):
Federal	$	11,035			16,663			19,476
State		788			1,668			1,950
Foreign		(3,484	)		290			(899	)
Total deferred		8,340			18,621			20,527
	$	31,531		$	20,808		$	(13,508	)

Reconciliation of expected federal income tax expense to actual

The provision for income taxes differs from the amount computed by applying the statutory federal tax rate to income before income taxes.  The sources and tax effects of the differences in the total income tax (benefit) provision from continuing operations are as follows (amounts in thousands):

	Year Ended March 31,
	2011			2010			2009
Computed expected income tax provision	$	161,244		$	83,235		$	81,228
State income taxes, net of federal benefits		1,746			915			1,295
Research and development tax credits		(3,691	)		(1,500	)		(2,732	)
Foreign income taxed at lower than the federal rate		(103,373	)		(53,390	)		(43,452	)
Tax benefit from audit settlements net of restructuring taxes		(24,395	)		(8,452	)		(16,880	)
Release of tax reserves		---			---			(32,967	)
	$	31,531		$	20,808		$	(13,508	)

Schedule of deferred tax assets and liabilities

The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are as follows (amounts in thousands):

	March 31,
	2011			2010
Deferred tax assets:
Deferred intercompany profit	$	11,031		$	7,711
Deferred income on shipments to distributors		33,304			24,531
Inventory valuation		5,740			842
Net operating loss carryforward		2,051			4,995
Share-based compensation		25,195			30,316
Income tax credits		50,795			45,171
Accrued expenses and other		11,052			9,512
Gross deferred tax assets		139,168			123,078
Valuation allowances		(50,346	)		(45,268	)
Net deferred tax assets		88,822			77,810
Deferred tax liabilities:
Income tax credits		17,852			---
Net operating loss carryforward		833			---
Property, plant and equipment, principally due to differences in depreciation		(5,036	)		(3,861	)
Junior convertible debentures		(407,477	)		(372,252	)
Other		(5,699	)		(600	)
Gross deferred tax liability		(399,527	)		(376,713	)
Net deferred tax liability	$	(310,705	)	$	(298,903	)