GOODWILL AND INTANGIBLE ASSETS - Intangible Assets, Net by Major Class (Details) - USD ($) $ in Thousands	Dec. 25, 2021	Dec. 26, 2020
Finite-lived intangible assets
Gross	$ 1,672,415	$ 1,334,244
Accumulated Amortization	(611,223)	(546,645)
Net	1,061,192	787,599
Backlog
Finite-lived intangible assets
Gross	12,577	29,233
Accumulated Amortization	(9,517)	(29,233)
Net	3,060	0
Technology
Finite-lived intangible assets
Gross	135,764	130,907
Accumulated Amortization	(95,454)	(81,305)
Net	40,310	49,602
Trademarks and trade names
Finite-lived intangible assets
Gross	13,086	15,870
Accumulated Amortization	(3,448)	(5,648)
Net	9,638	10,222
Other
Finite-lived intangible assets
Gross	35,231	20,903
Accumulated Amortization	(8,445)	(14,633)
Net	26,786	6,270
Other intangible assets
Finite-lived intangible assets
Gross	196,658	196,913
Accumulated Amortization	(116,864)	(130,819)
Net	79,794	66,094
Client relationships
Finite-lived intangible assets
Gross	1,475,757	1,137,331
Accumulated Amortization	(494,359)	(415,826)
Net	$ 981,398	$ 721,505