Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 27, 2021	Jun. 28, 2020
Statement of Cash Flows [Abstract]
Net earnings (loss)	$ 95.6	$ (100.8)
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation of plant and equipment	67.6	56.6
Amortization of intangibles	62.6	71.5
Asset impairments	0.0	40.9
Loss on assets held for sale	101.8	0.0
Program cost amortization	208.2	182.8
Deferred income taxes	43.6	(11.1)
Stock-based compensation	37.1	26.1
Other non-cash items	0.2	0.0
Change in operating assets and liabilities net of acquired balances:
Decrease in accounts receivable	533.9	722.0
Increase in inventories	(109.5)	(125.4)
Decrease (increase) in prepaid expenses and other current assets	38.8	(40.2)
Program spend, net	(308.3)	(220.4)
Decrease in accounts payable and accrued liabilities	(169.3)	(344.4)
Change in net deemed repatriation tax	(18.4)	0.0
Other	(6.8)	0.6
Net cash provided by operating activities	577.1	258.2
Cash flows from investing activities:
Additions to property, plant and equipment	(63.1)	(64.0)
Acquisitions, net of cash acquired	0.0	(4,403.9)
Other	(3.2)	13.1
Net cash utilized by investing activities	(66.3)	(4,454.8)
Cash flows from financing activities:
Proceeds from borrowings with maturity greater than three months	114.7	1,023.5
Repayments of borrowings with maturity greater than three months	(635.0)	(98.2)
Net repayments of other short-term borrowings	(6.3)	(4.5)
Stock-based compensation transactions	9.4	1.8
Dividends paid	(187.5)	(186.2)
Payments related to tax withholding for share-based compensation	(9.5)	(5.7)
Redemption of equity instruments	0.0	(47.4)
Other	(4.2)	(4.8)
Net cash (utilized) provided by financing activities	(718.4)	678.5
Effect of exchange rate changes on cash	4.3	(24.4)
Net decrease in cash, cash equivalents and restricted cash	(203.3)	(3,542.5)
Net change due to cash classified as held for sale	(18.2)	0.0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Total	(221.5)	(3,542.5)
Cash, cash equivalents and restricted cash at beginning of year	1,449.7	4,580.4
Cash, cash equivalents and restricted cash at end of period	1,228.2	1,037.9
Cash paid during the period for:
Interest	90.2	81.5
Income taxes	$ 70.8	$ 30.4