Income taxes (Tables)

12 Months Ended

Mar. 31, 2016

Components of income tax expense (benefit)

The income tax provision consists of the following (amounts in thousands):



	Year Ended March 31,
	2016			2015			2014
Pretax Income:
U.S.	$	(75,515	)	$	(944	)	$	28,245
Foreign	356,808			346,851			404,109
	$	281,293		$	345,907		$	432,354
Current expense (benefit):
U.S. Federal	$	(3,966	)	$	(3,185	)	$	992
State	(188		)	(24		)	64
Foreign	21,947			16,602			30,697
Total current	$	17,793		$	13,393		$	31,753
Deferred expense (benefit):
U.S. Federal	$	(42,207	)	$	(22,641	)	$	14,445
State	(1,990		)	(1,562		)	929
Foreign	(16,228		)	(8,608		)	(10,054		)
Total deferred	(60,425		)	(32,811		)	5,320
Total	$	(42,632	)	$	(19,418	)	$	37,073

Reconciliation of expected federal income tax expense to actual

The sources and tax effects of the differences in the total income tax provision are as follows (amounts in thousands):



	Year Ended March 31,
	2016			2015			2014
Computed expected income tax provision	$	98,453		$	121,067		$	151,324
State income taxes, net of federal benefits	(1,246		)	(20		)	686
Research and development tax credits - current year	(13,542		)	(9,703		)	(4,875		)
Research and development tax credits - prior years	(2,511		)	(1,789		)	1,600
Foreign income taxed at lower than the federal rate	(114,497		)	(106,939		)	(116,003		)
Increases related to current and prior year tax positions	14,462			19,769			16,809
Decreases related to prior year tax positions ⁽¹⁾	(12,103		)	(33,100		)	(14,581		)
Withholding taxes	5,970			5,218			6,212
Change in valuation allowance	(2,482		)	(14,286		)	—
Intercompany prepaid tax asset amortization	(15,493		)	(1,089		)	—
Other	357			1,454			(4,099		)
Total	$	(42,632	)	$	(19,418	)	$	37,073

⁽¹⁾ The release of prior year tax positions during fiscal 2016 increased each of the basic and diluted net income per common share by $0.06. The release of prior year tax positions during fiscal 2015 increased the basic and diluted net income per common share by $0.16 and $0.15, respectively. The release of prior year tax positions during fiscal 2014 increased each of the basic and diluted net income per common share by $0.07.

Schedule of deferred tax assets and liabilities

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



	March 31,
	2016			2015
Deferred tax assets:
Deferred intercompany profit	$	12,642		$	10,865
Deferred income on shipments to distributors	34,830			34,493
Inventory valuation	12,082			9,605
Net operating loss carryforward	63,209			105,756
Capital loss carryforward	5,707			4,582
Share-based compensation	31,410			26,780
Income tax credits	100,294			115,893
Property, plant and equipment, principally due to differences in depreciation	16,262			2,236
Accrued expenses and other	7,559			671
Gross deferred tax assets	283,995			310,881
Valuation allowances	(161,834		)	(116,482		)
Deferred tax assets, net of valuation allowances	122,161			194,399
Deferred tax liabilities:
Convertible debentures	(496,626		)	(493,897		)
Other	(9,922		)	(10,649		)
Deferred tax liabilities	(506,548		)	(504,546		)
Net deferred tax liability	$	(384,387	)	$	(310,147	)

Reported as:
Current deferred tax assets	$	—		$	71,045
Non-current deferred tax assets	14,831			—
Non-current deferred tax liability	(399,218		)	(381,192		)
Net deferred tax liability	$	(384,387	)	$	(310,147	)

Rollforward of unrecognized tax benefits

The following table summarizes the activity related to the Company's gross unrecognized tax benefits from April 1, 2013 to March 31, 2016 (amounts in thousands):



	Year Ended March 31,
	2016			2015			2014
Beginning balance	$	170,654		$	149,878		$	152,845
Increases related to acquisitions	46,245			8,381			341
Decreases related to settlements with tax authorities	(7,954		)	(20,197		)	(15,016		)
Decreases related to statute of limitation expirations	(4,591		)	(9,031		)	(4,069		)
Increases related to current year tax positions	16,315			23,179			14,669
Increases related to prior year tax positions	—			18,444			1,108
Ending balance	$	220,669		$	170,654		$	149,878