Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
Mar. 29, 2019	Mar. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 1,354	$ 24,741
Other comprehensive income (loss):
Change in cumulative translation adjustment	(867)	336
Cash flow hedges:
Change in fair value of derivatives	15	9
Adjustment for net gain (loss) realized and included in net income	(24)	(886)
Total change in unrealized loss on derivative instruments	(9)	(877)
Other comprehensive loss, net of tax	(876)	(541)
Comprehensive income	478	24,200
Less: Comprehensive income attributable to noncontrolling interest	749
Comprehensive income (loss) attributable to Ultra Clean Holdings, Inc.	$ (271)	$ 24,200

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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