Income taxes (Tables)

12 Months Ended

Dec. 31, 2012

Income Tax Disclosure [Abstract]

Schedule of Provision for (Benefit from) Income Taxes on Continuing Operations

The provision for (benefit from) income taxes on continuing operations in the accompanying consolidated statements of operations consists of the following:

	Year Ended December 31,
(U.S. Dollars, in thousands)	2012		2011			2010
	(Restated)		(Restated)			(Restated)
U.S.
Current	$	17,897	$	25,148		$	19,336
Deferred		1,788		(12,657	)		2,282
Total U.S		19,685		12,491			21,618
Non-U.S.
Current		4,609		2,735			253
Deferred		844		(1,061	)		2,160
		5,453		1,674			2,413
Total tax expense	$	25,138	$	14,165		$	24,031

Schedule of Tax Effects of Significant Temporary Differences Comprising Deferred Tax Assets and Liabilities

The tax effects of the significant temporary differences, which comprise the deferred tax assets and liabilities, are as follows:

	Year Ended December 31,
(U.S. Dollars, in thousands)	2012			2011
	(Restated)			(Restated)
Intangible assets and goodwill	$	5,346		$	5,300
Inventories and related reserves		14,020			13,756
Deferred revenue and cost of sales		11,682			7,631
Other accruals and reserves		3,868			10,287
Accrued compensation		3,817			4,444
Allowance for doubtful accounts		3,718			4,029
Accrued interest		18,229			16,123
Net operating loss carryforwards		27,231			20,849
Other, net		539			(349	)
		88,450			82,070
Valuation allowance		(26,361	)		(19,124	)
Deferred tax asset	$	62,089		$	62,946
Withholding taxes		(11,456	)		(9,778	)
Property, plant and equipment		(9,758	)		(9,892	)
Deferred tax liability		(21,214	)		(19,670	)
Net deferred tax assets	$	40,875		$	43,276

Schedule of Effective Income Tax Rate Reconciliation for Continuing Operations

The rate reconciliation for continuing operations presented below is based on the U.S. federal income tax rate, rather than the parent company’s country of domicile tax rate. Management believes, given the large proportion of taxable income earned in the United States, such disclosure is more meaningful.

(US$ in thousands, except percentages)	2012						2011						2010
	Amount			Percent			Amount			Percent			Amount			Percent
	(Restated)			(Restated)			(Restated)			(Restated)			(Restated)			(Restated)
Statutory U.S. federal income tax rate	$	24,565			35.0	%	$	(719	)		35.0	%	$	19,261			35.0	%
State taxes, net		1,708			2.4	%		1,896			(92.4	)%		2,051			3.7	%
Foreign rate differential		(3,115	)		(4.4	)%		1,585			(77.2	)%		251			0.5	%
Valuation allowance—foreign losses		6,183			8.8	%		4,882			(237.8)	%		3,497			6.4	%
SRL Intangible		(2,214	)		(3.2	)%		(2,421	)		117.9	%		(2,607	)		(4.7	)%
Domestic manufacturing deduction		(1,694	)		(2.4	)%		(1,703	)		82.9	%		(1,529	)		(2.8	)%
Withholding Taxes		1,679			2.4	%		1,676			(81.6	)%		1,687			3.1	%
Settlement of U.S. Government resolutions		(1,260	)		(1.8	)%		9,520			(463.7	)%		—			—	%
Other items, net		(714	)		(1.0	)%		(551	)		26.9	%		1,420			2.5	%
Income tax expense/effective rate	$	25,138			35.8	%	$	14,165			(690.0	)%	$	24,031			43.7	%

Schedule of Gross Unrecognized Tax Benefits (Excluding Interest and Penalties)

A reconciliation of the gross unrecognized tax benefits (excluding interest and penalties) for the years ended December 31, 2012 and December 31, 2011 follows:

(U.S. Dollars, in thousands)	2012			2011
	(Restated)			(Restated)
Balance as of January 1,	$	610		$	569
Additions for current year tax positions		793			86
Decreases for prior year tax positions		(106	)		(17	)
Expiration of statutes		(108	)		(28	)
Balance as of December 31,	$	1,189		$	610