Consolidated Statement of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Jan. 03, 2014	$ 542,055	$ 24	$ 344,915	$ (1,232)	$ 183,990	$ 14,358
Balance, shares at Jan. 03, 2014		24,459		(37)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	55,458				55,458
Total other comprehensive income (loss)	(5,235)					(5,235)
Stock-based compensation	8,921		8,921
Net shares issued (acquired)	3,465	$ 1	7,754	$ (4,290)
Net shares issued under stock incentive plans, shares		640		(86)
Excess tax benefit on share-based compensation	4,357		4,357
Shares contributed to 401(k) Plan	4,341	$ 0	126	$ 4,215
Shares contributed to 401(k) Plan, shares		0		95
Shares issued in connection with acquisition	0
Issuance of roll-over options in connection with acquisition	0
Balance at Jan. 02, 2015	613,362	$ 25	366,073	$ (1,307)	239,448	9,123
Balance, shares at Jan. 02, 2015		25,099		(28)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(7,594)				(7,594)
Total other comprehensive income (loss)	(7,753)					(7,753)
Stock-based compensation	9,364		9,364
Net shares issued (acquired)	504	$ 1	5,764	$ (5,261)
Net shares issued under stock incentive plans, shares		585		(107)
Excess tax benefit on share-based compensation	5,639		5,639
Shares contributed to 401(k) Plan	3,920	$ 0	452	$ 3,468
Shares contributed to 401(k) Plan, shares		0		72
Shares issued in connection with acquisition	245,368	$ 5	245,363	$ 0
Issuance of shares in connection with acquisition, shares		4,980		0
Issuance of roll-over options in connection with acquisition	4,508		4,508
Purchase of non-controlling interests in subsidiaries	(16,693)		(16,693)
Balance at Jan. 01, 2016	850,625	$ 31	620,470	$ (3,100)	231,854	1,370
Balance, shares at Jan. 01, 2016		30,664		(63)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	5,961				5,961
Total other comprehensive income (loss)	(17,370)					(17,370)
Stock-based compensation	8,408		8,408
Net shares issued (acquired)	(1,164)	$ 0	1,570	$ (2,734)
Net shares issued under stock incentive plans, shares		395		(71)
Excess tax benefit on share-based compensation	2,266		2,266
Shares contributed to 401(k) Plan	0
Shares issued in connection with acquisition	0
Issuance of roll-over options in connection with acquisition	0
Spin-off of Nuvectra Corporation	(123,487)		5,241		(128,728)
Balance at Dec. 30, 2016	$ 725,239	$ 31	$ 637,955	$ (5,834)	$ 109,087	$ (16,000)
Balance, shares at Dec. 30, 2016		31,059		(134)