CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited)	3 Months Ended	6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Current assets:
Cash and cash equivalents	$ 1,963,200,000	$ 1,963,200,000	$ 1,320,800,000
Accounts Receivable, after Allowance for Credit Loss, Current	2,210,100,000	2,210,100,000	2,479,800,000
Unbilled Contracts Receivable	637,000,000.0	637,000,000.0	536,800,000
Supplies inventories	421,300,000	421,300,000	423,200,000
Prepaid expenses and other	461,900,000	461,900,000	364,800,000
Total current assets	5,693,500,000	5,693,500,000	5,125,400,000
Property, plant and equipment, net	2,701,800,000	2,701,800,000	2,729,600,000
Goodwill, net	7,744,500,000	7,744,500,000	7,751,500,000
Intangible Assets, Net (Excluding Goodwill)	3,753,800,000	3,753,800,000	3,961,100,000
Joint venture partnerships and equity method investments	82,100,000	82,100,000	73,500,000
Deferred Income Taxes and Other Assets, Current	23,700,000	23,700,000	20,600,000
Other assets, net	417,700,000	417,700,000	410,000,000.0
Total assets	20,417,100,000	20,417,100,000	20,071,700,000
Liabilities, Current [Abstract]
Accounts Payable, Current	599,900,000	599,900,000	638,900,000
Accrued Liabilities, Current	1,317,900,000	1,317,900,000	1,357,700,000
Deferred Revenue, Current	546,700,000	546,700,000	506,500,000
Operating Lease, Liability, Current	190,000,000.0	190,000,000.0	192,000,000.0
Finance Lease, Liability, Current	10,800,000	10,800,000	6,700,000
Current debt excluding finance lease liability	1,800,000	1,800,000	376,700,000
Long-term debt, less current portion	2,667,100,000	2,667,100,000	3,078,500,000
Long-term Debt, Excluding Current Maturities	5,422,600,000	5,422,600,000	5,419,000,000.0
Commitments and contingent liabilities	502,900,000	502,900,000	526,400,000
Operating Lease, Liability, Noncurrent	645,200,000	645,200,000	677,600,000
Finance Lease, Liability, Noncurrent	87,200,000	87,200,000	84,400,000
Deferred income taxes and other tax liabilities	826,000,000.0	826,000,000.0	905,400,000
Noncontrolling interest	10,151,000,000.0	10,151,000,000.0	10,691,300,000
Shareholders' equity:
Common stock, 92.8 and 93.5 shares outstanding at March 31, 2013 and December 31, 2012, respectively	21,000,000.0	21,000,000.0	20,700,000
Additional paid-in capital	0	0	110,300,000
Retained earnings	8,900,000	8,900,000	9,000,000.0
Accumulated other comprehensive income	(10,417,400,000)	(10,417,400,000)	(9,402,300,000)
Total liabilities and shareholders' equity	(181,200,000)	(181,200,000)	(161,900,000)
Stockholders' Equity Attributable to Parent	10,245,100,000	10,245,100,000	9,359,700,000
Liabilities and Equity	20,417,100,000	20,417,100,000	$ 20,071,700,000
Repayments of Senior Debt		1,000,000,000.0
Net earnings	$ 468,000,000.0	$ 1,238,100,000