Revenue and Contracts with Customers (Contract with Customer Asset and Liability) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Deferred costs associated with deferred revenue	$ 145.4	$ 145.4		$ 144.1
Provision for Loss on Contracts	8.9	8.9
Provision for Loss on Contract Change		(1.1)
Provision for loss on contracts, noncurrent	0.7	0.7
Provision for Loss on Contract Noncurrent Change		(7.6)
Loss on contracts			$ 0.0
Deferred revenue	248.2	248.2		243.0
Deferred revenue – change		5.2
Advances from customers, current	1.5	1.5		23.3
Customer advances – change		(21.8)
Advances from customer, noncurrent	44.9	44.9		29.4
Advances from customers, noncurrent - change		15.5
Deferred revenue, additions		5.2
Deferred revenue, revenue recognized		(5.2)
Provision for Loss on Contracts Total	9.6	9.6
Provision for Loss on Contracts Utilized	3.4	8.7
Government [Member]
Provision for Loss on Contracts	8.9	8.9		10.0
Provision for loss on contracts, noncurrent	$ 0.7	$ 0.7		$ 8.3