Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 28, 2019	Jun. 29, 2018	Jun. 28, 2019	Jun. 29, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (254)	$ 18,960	$ 1,100	$ 43,701
Other comprehensive income (loss):
Change in cumulative translation adjustment	(1,287)	(799)	(2,154)	(463)
Cash flow hedges:
Change in fair value of derivatives	77	(71)	92	(62)
Adjustment for net loss realized and included in net income (loss)	(22)	(24)	(46)	(910)
Total change in unrealized gain (loss) on derivative instruments	55	(95)	46	(972)
Other comprehensive loss, net of tax	(1,232)	(894)	(2,108)	(1,435)
Comprehensive income (loss)	(1,486)	18,066	(1,008)	42,266
Less: Comprehensive income (loss) attributable to noncontrolling interest	(52)		697
Comprehensive income (loss) attributable to Ultra Clean Holdings, Inc.	$ (1,434)	$ 18,066	$ (1,705)	$ 42,266

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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