Other Income (Expense)—Net (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Other Income and Expenses [Abstract]
Interest income	$ 2,156,000	$ 1,026,000	$ 799,000
Gain on Skagen Designs arbitration settlement	0	0	5,968,000
Gain on interest rate swap settlement	0	5,241,000	0
Equity in losses of unconsolidated investment	(1,321,000)	0	0
Gain on machine vision divestiture	3,500,000	0	0
Currency gains	8,729,345	32,611,000	20,000
Other net gains	992,000	1,565,000	653,000
Other income (expense) - net	$ 14,056,000	$ 40,443,000	$ 7,440,000