Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2020	Dec. 27, 2019	Dec. 28, 2018
Revenues:
Total revenues	$ 1,398,600	$ 1,066,200	$ 1,096,500
Cost of revenues:
Total cost revenues	1,106,800	869,400	920,700
Gross margin	291,800	196,800	175,800
Operating expenses:
Research and development	14,800	14,600	13,300
Sales and marketing	25,100	22,400	16,300
General and administrative	130,500	129,900	85,500
Total operating expenses	170,400	166,900	115,100
Income from operations	121,400	29,900	60,700
Interest income	900	400	300
Interest expense	16,900	25,600	10,000
Other income (expense), net	(5,700)	(2,400)	1,300
Income before provision for income taxes	99,700	2,300	52,300
Provision for income taxes	19,300	10,000	15,300
Net income (loss)	80,400	(7,700)	37,000
Less: Net income attributable to noncontrolling interests	2,800	1,700	400
Net income (loss) attributable to UCT	$ 77,600	$ (9,400)	$ 36,600
Net income (loss) per share attributable to UCT common stockholders:
Basic	$ 1.93	$ (0.24)	$ 0.95
Diluted	$ 1.89	$ (0.24)	$ 0.94
Shares used in computing net income (loss) per share:
Basic	40.2	39.5	38.4
Diluted	41.1	39.5	38.9
Product [Member]
Revenues:
Product	$ 1,131,200	$ 840,800	$ 1,015,500
Cost of revenues:
Product	934,700	719,000	865,200
Services [Member]
Revenues:
Product	267,400	225,400	81,000
Cost of revenues:
Product	$ 172,100	$ 150,400	$ 55,500