Financial Instruments Measured at Fair Value - AFS (Details) - USD ($) $ in Thousands	Apr. 01, 2017	Dec. 31, 2016
Marubun [Member]
Schedule of Available-for-sale Securities [Line Items]
Available For Sale Investment Ownership Percentage	8.40%
Cost basis	$ 10,016	$ 10,016
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax	5,059	3,806
Fair value	15,075	13,822
Mutual Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost basis	18,147	18,097
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax	7,555	5,996
Fair value	$ 25,702	$ 24,093