Fair value measurements (Tables)

9 Months Ended

Sep. 30, 2014

Fair Value Disclosures [Abstract]

Schedule of Financial Assets and Liabilities Recorded at Fair Value on Recurring Basis

The fair value of the Company’s financial assets and liabilities on a recurring basis were as follows:

(U.S. Dollars in thousands)	Balance September 30, 2014			Level 1		Level 2			Level 3
Assets
Collective trust funds	$	1,635		$	—	$	1,635		$	—
Treasury securities		610			610		—			—
Certificates of deposit		1,595			1,595		—			—
Derivative securities		2,167			—		2,167			—
Other investments		1,250			—		1,250			—
Total	$	7,257		$	2,205	$	5,052		$	—
Liabilities
Deferred compensation plan	$	(1,927	)	$	—	$	(1,927	)	$	—
Total	$	(1,927	)	$	—	$	(1,927	)	$	—

(U.S. Dollars in thousands)	Balance December 31, 2013			Level 1			Level 2			Level 3
	(Restated)
Assets
Collective trust funds	$	1,667		$	—		$	1,667		$	—
Treasury securities		660			660			—			—
Certificates of deposit		1,562			1,562			—			—
Derivative securities		107			—			107			—
Total	$	3,996		$	2,22 2		$	1,774		$	—
Liabilities
Deferred compensation plan	$	(2,506	)	$	—		$	(2,506	)	$	—
Derivative securities
Cross-currency hedge		(1,036	)		—			(1,036	)		—
Total	$	(3,542	)	$	(2,506	)	$	(3,542	)	$	—