Shareholders' equity (Tables)

12 Months Ended

Dec. 31, 2019

Stockholders Equity Note [Abstract]

Components of Changes in Accumulated Other Comprehensive Income (Loss)

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

(U.S. Dollars, in thousands)	Currency Translation Adjustments			Debt Security			Accumulated Other Comprehensive Income (Loss)
Balance at December 31, 2017	$	(563	)	$	4,350		$	3,787
Other comprehensive income (loss)		(1,823	)		1,770			(53	)
Income taxes		—			(438	)		(438	)
Balance at December 31, 2018	$	(2,386	)	$	5,682		$	3,296
Cumulative effect adjustment from adoption of ASU 2018-02		—			937			937
Other comprehensive loss		(653	)		(2,593	)		(3,246	)
Income taxes		—			642			642
Reclassification adjustment to:
Interest income (expense), net		—			(1,034	)		(1,034	)
Other expense, net		—			(5,193	)		(5,193	)
Income taxes		—			1,559			1,559
Balance at December 31, 2019	$	(3,039	)	$	—		$	(3,039	)