Summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2012

Schedule of Useful Lives

The useful lives are as follows:

	Years
Buildings		25 to 33
Plant and equipment		2 to 10
Furniture and fixtures		4 to 8
Instrumentation		3 to 4

Components of Changes in Accumulated Other Comprehensive Income

The components of and changes in accumulated other comprehensive income are as follows:

(US$ in thousands)	Foreign Currency Translation Adjustments			Fair Value of Cross- Currency Swaps			Accumulated Other Comprehensive Income (Loss)
Balance at December 31, 2010	$	5,085		$	305		$	5,390
Unrealized loss on cross-currency swaps, net of tax benefit of $256		—			(437	)		(437	)
Foreign currency translation adjustment (1)		(3,192	)		—			(3,192	)
Balance at December 31, 2011		1,893			(132	)		1,761
Unrealized gain on cross-currency swaps, net of tax of $153		—			263			263
Foreign currency translation adjustment (1)		480			—			480
Balance at December 31, 2012	$	2,373		$	131		$	2,504

(1) As the cash generally remains permanently invested in the non U.S. dollar denominated foreign subsidiaries, no deferred taxes are recognized on the related foreign currency translation adjustment.