Contract Assets and Contract Liabilities - Change in Carrying Amount of Contract Assets and Contract Liabilities (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Contract Assets
Balance at beginning of year	$ 544.2	$ 623.4
Acquisitions	0.0	4.1
Recognized in current year	369.5	451.8
Reclassified to accounts receivable	(364.0)	(519.1)
Foreign currency impact	(4.5)	(6.2)
Balance at end of period	545.2	554.0
Contract Liabilities
Balance at beginning of year	831.2	799.7
Acquisitions	1.7	6.8
Recognized in current year	339.3	424.7
Amounts in beginning balance reclassified to revenue	(316.7)	(333.9)
Current year amounts reclassified to revenue	(63.3)	(107.5)
Foreign currency impact	(6.1)	(12.0)
Balance at end of period	$ 786.1	$ 777.8