Fair value measurements (Tables)

3 Months Ended

Mar. 31, 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 March 31, 2014			Level 1		Level 2			Level 3
Assets					(Restated1)
Collective trust funds	$	1,652		$	—	$	1,652		$	—
Treasury securities		661			661		—			—
Certificates of deposit		1,630			1,630		—			—
Derivative securities		107			—		107			—
Total	$	4,050		$	2,291	$	1,759		$	—
Liabilities
Deferred compensation plan	$	(1,970	)	$	—	$	(1,970	)	$	—
Derivative securities		(1,035	)		—		(1,035	)		—
Total	$	(3,005	)	$	—	$	(3,005	)	$	—
(U.S. Dollars in thousands)	Balance December 31, 2013			Level 1		Level 2			Level 3
Assets					(Restated1)
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		$	2,222	$	1,774		$	—
Liabilities
Deferred compensation plan	$	(2,506	)	$	—	$	(2,506	)	$	—
Derivative securities		(1,036	)		—		(1,036	)		—
Total	$	(3,542	)	$	—	$	(3,542	)	$	—

(1) The Company has changed the presentation to breakout and provide more description of assets and to include financial instruments not previously included in the table above.