Consolidated Statements of Cash Flows $ in Thousands	12 Months Ended
	Dec. 28, 2019 USD ($)	Dec. 29, 2018 USD ($)	Dec. 30, 2017 USD ($)
Cash flows from operating activities:
Net income (loss) attributable to Cohu	$ (69,700)	$ (32,181)	$ 32,843
Net income (loss) from noncontrolling interest	8	(243)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Loss on impairment and disposal of segments held for sale (Note 13)	1,138		278
Interest capitalized associated with cloud computing implementation	(168)
Gain on divestiture of consolidated entity	(149)
Depreciation and amortization	58,871	26,047	9,195
Share-based compensation expense including restructuring charges	14,148	18,279	7,007
Amortization of inventory step-up and inventory related charges	8,347	24,179	1,404
Amortization of debt discounts and issuance costs	1,110
Accrued retiree benefits	1,017	(560)	322
Deferred income taxes	(5,385)	(8,207)	(3,791)
Adjustment to contingent consideration liability		657	1,423
Changes in other assets	(3,044)	(2,961)	1,501
(Gain) loss on disposal of fixed assets	173	293	(42)
Changes in other accrued liabilities	5,348	198	979
Changes in current assets and liabilities, excluding effects from acquisitions and divestitures:
Accounts receivable	21,150	5,785	(3,259)
Inventories	26	2,043	(12,196)
Accrued compensation, warranty and other liabilities	2,143	3,985	937
Accounts payable	(3,122)	(7,103)	4,157
Deferred profit	997	37	(442)
Other current assets	(5,996)	148	952
Income taxes payable	(10,719)	4,041	(1,518)
Operating lease right-of-use assets	7,159
Current and long-term operating lease liabilities	(6,083)
Net cash provided by operating activities	17,269	34,437	39,750
Cash flows from investing activities, excluding effects from acquisitions and divestitures:
Purchases of property, plant and equipment	(18,000)	(4,967)	(6,093)
Net cash received from sale of land, facility and assets	1,767	1,005	104
Purchases of short-term investments	(315)	(38,700)	(37,010)
Sales and maturities of short-term investments		59,469	47,671
Net cash used in investing activities	(16,548)	(322,308)	(7,044)
Cash flows from financing activities:
Cash dividends paid	(9,827)	(6,949)	(6,577)
Proceeds from construction loan	5,477
Repayments of long-term debt	(3,817)	(2,323)	(1,631)
Issuance (repurchases) of common stock, net including awards settled in cash	(16)	(8,978)	10,353
Proceeds from Term B Loan		348,250
Payment of debt issuance costs		(7,072)
Payment of contingent consideration		(823)
Net cash provided by (used in) financing activities	(8,183)	322,105	2,145
Effect of exchange rate changes on cash and cash equivalents	(1,529)	(3,599)	3,390
Net increase (decrease) in cash and cash equivalents	(8,991)	30,635	38,241
Cash and cash equivalents at beginning of year	164,921	134,286	96,045
Cash and cash equivalents at end of year	155,930	164,921	134,286
Cash held by discontinued operations (Note 13)	(736)	(461)
Cash and cash equivalents at end of year from continuing operations	155,194	164,460	134,286
Supplemental disclosure of cash flow information:
Cash paid during the year for income taxes	14,942	6,243	7,094
Cash paid for interest	14,846	4,977
Dividends declared but not yet paid	2,484	2,445	1,705
Property, plant and equipment purchases included in accounts payable	1,601	599	260
Inventory capitalized as capital assets	300	857	190
Xcerra [Member]
Cash flows from investing activities, excluding effects from acquisitions and divestitures:
Payment for purchase of business, net of cash received		(339,115)
Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member]
Cash flows from investing activities, excluding effects from acquisitions and divestitures:
Payment for purchase of business, net of cash received			$ (11,716)