Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Jan. 02, 2016	Dec. 27, 2014	Dec. 28, 2013
Operating activities
Net income	$ 82,466,000	$ 99,418,000	$ 88,784,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	29,701,000	29,374,000	25,201,000
Amortization of Intangible Assets	$ 11,898,000	12,501,000	$ 9,279,000
Impairment of assets		293,000
Provision for bad debts	$ 164,000	130,000	$ 289,000
Non-cash inventory charge		$ 2,769,000	$ 1,525,000
Net loss on pension settlement, net of tax	$ 19,308,000
Impairment And Equity In Net Loss Of Unconsolidated Affiliate			$ 10,678,000
Loss on sale of property, plant and equipment	$ 1,253,000	$ 1,042,000	92,000
Stock-based compensation	10,266,000	9,069,000	8,609,000
Excess tax benefit on share-based compensation	(1,891,000)	(2,843,000)	(4,054,000)
Deferred income taxes	11,479,000	(4,488,000)	6,640,000
Changes in operating assets and liabilities:
Accounts receivable	(14,377,000)	(13,062,000)	(16,683,000)
Inventories	(3,577,000)	(2,258,000)	(5,486,000)
Accounts payable	2,573,000	17,281,000	2,000,000
Accrued expenses (including post-retirement)	6,482,000	(1,577,000)	(8,906,000)
Accrued payroll and severance	5,883,000	2,360,000	8,032,000
Accrued taxes	(1,043,000)	(549,000)	(10,773,000)
Prepaid expenses and other	5,241,000	3,681,000	2,140,000
Net cash provided by operating activities	165,826,000	153,141,000	117,367,000
Investing activities
Acquisitions of businesses, net of cash acquired	$ (4,558,000)	(56,368,000)	(144,382,000)
Purchases of short-term investments		$ (4,331,000)	$ (8,478,000)
Purchase of cost method investment	$ (3,500,000)
Proceeds from maturities of short-term investments		$ 6,770,000	$ 2,044,000
Decrease (increase) in entrusted loan receivable (see note 7)	$ 7,811,000	(17,908,000)
Purchases of property, plant and equipment	(44,019,000)	(32,281,000)	$ (34,953,000)
Proceeds from sale of property, plant and equipment	102,000	125,000	176,000
Net cash used in investing activities	(44,164,000)	(103,993,000)	(185,593,000)
Financing activities:
Proceeds from debt	49,000,000	97,500,000	260,500,000
Payments of term debt	(8,750,000)	(5,000,000)	(1,250,000)
Payments of revolving credit facility	(55,500,000)	(135,000,000)	(123,500,000)
Proceeds from exercise of stock options	9,150,000	14,061,000	$ 21,959,000
(Payments) proceeds from entrusted loan (see note 7)	(7,811,000)	17,908,000
Debt issuance costs	(42,000)	(107,000)	$ (809,000)
Cash dividends paid	(24,341,000)	(21,175,000)	(18,722,000)
Excess tax benefit on share-based compensation	1,891,000	2,843,000	$ 4,054,000
Purchases of common stock	(31,252,000)	(14,283,000)
Net cash (used in) provided by financing activities	(67,655,000)	(43,253,000)	$ 142,232,000
Effect of exchange rate changes on cash and cash equivalents	(22,792,000)	(13,516,000)	(4,218,000)
Increase (decrease) in cash and cash equivalents	31,215,000	(7,621,000)	69,788,000
Cash and cash equivalents at beginning of year	297,571,000	305,192,000	235,404,000
Cash and cash equivalents at end of year	$ 328,786,000	$ 297,571,000	$ 305,192,000