Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 27, 2019	Dec. 28, 2018	Dec. 29, 2017
Revenues:
Total revenues	$ 1,066,200	$ 1,096,500	$ 924,400
Cost of revenues:
Total cost revenues	869,400	920,700	756,700
Gross margin	196,800	175,800	167,700
Operating expenses:
Research and development	14,600	13,300	11,700
Sales and marketing	22,400	16,300	13,700
General and administrative	129,900	85,500	52,800
Total operating expenses	166,900	115,100	78,200
Income from operations	29,900	60,700	89,500
Interest income	400	300	100
Interest expense	25,600	10,000	2,200
Other income (expense), net	(2,400)	1,300	(400)
Income before provision for income taxes	2,300	52,300	87,000
Provision for income taxes	10,000	15,300	11,900
Net income (loss)	(7,700)	37,000	75,100
Less: Net income attributable to noncontrolling interests	1,700	400
Net income (loss) attributable to UCT	$ (9,400)	$ 36,600	$ 75,100
Net income (loss) per share attributable to UCT common stockholders:
Basic	$ (0.24)	$ 0.95	$ 2.25
Diluted	$ (0.24)	$ 0.94	$ 2.19
Shares used in computing net income (loss) per share:
Basic	39.5	38.4	33.4
Diluted	39.5	38.9	34.3
Product [Member]
Revenues:
Product	$ 840,800	$ 1,015,500	$ 924,400
Cost of revenues:
Product	719,000	865,200	$ 756,700
Services [Member]
Revenues:
Product	225,400	81,000
Cost of revenues:
Product	$ 150,400	$ 55,500