Fair Value (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value [Abstract]

Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following tables present the fair value hierarchy for those assets and liabilities measured at fair value on a recurring basis as of December 31, 2014 and 2015 (U.S. dollars in thousands):

	Fair Value at December 31, 2014
	Level 1		Level 2		Level 3		Total
Financial assets (liabilities):
Cash equivalents and current investments	$	86,574	$	─	$	─	$	86,574
Forward contracts	─			1,661	─			1,661
Life insurance contracts	─		─			26,280		26,280
Total	$	86,574	$	1,661	$	26,280	$	114,515

	Fair Value at December 31, 2015
	Level 1		Level 2		Level 3		Total
Financial assets (liabilities):
Cash equivalents and current investments	$	47,121	$	─	$	─	$	47,121
Forward contracts	─			485	─			485
Life insurance contracts	─		─			27,292		27,292
Total	$	47,121	$	485	$	27,292	$	74,898

Changes in Fair Value of Level 3 Marketable Securities

The following table provides a summary of changes in fair value of the Company's Level 3 marketable securities (U.S. dollars in thousands):

Life Insurance Contracts	2014			2015
Beginning balance at January 1	$	23,172		$	26,280
Actual return on plan assets:
Relating to assets still held at the reporting date		1,249			(1,597	)
Purchases and issuances		2,798			3,025
Sales and settlements		(939	)		(416	)
Transfers into Level 3	─			─
Ending balance at December 31	$	26,280		$	27,292