Revenue from Contracts with Customers - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Revenue recognition [Line Items]
Inventories, net	$ 1,035,900,000		$ 1,035,900,000		$ 1,155,300,000
Adjustment from current cost to LIFO cost basis	(41,100,000)		(41,100,000)		(33,600,000)
Sales	598,000,000.0	$ 1,018,700,000	2,323,800,000	$ 3,103,900,000
Cost of sales	559,900,000	859,000,000.0	2,076,200,000	2,635,400,000
Short-term contract assets	41,700,000	37,800,000	41,700,000	37,800,000	38,500,000	$ 51,200,000
Long-term contract assets	0	100,000	0	100,000	100,000	100,000
Other current liabilities	213,000,000.0		213,000,000.0		237,800,000
Other long-term liabilities	212,300,000		212,300,000		160,800,000
Short-term contract liabilities	97,800,000	97,100,000	97,800,000	97,100,000	78,700,000	71,400,000
Long-term contract liabilities	31,900,000	7,300,000	$ 31,900,000	7,300,000	25,900,000	$ 7,300,000
Number of business segments | segment			2
Revenue, Performance Obligation [Abstract]
Confirmed order backlog	1,440,000,000	2,340,000,000	$ 1,440,000,000	2,340,000,000
Confirmed orders with current performance obligations	0.70		0.70
Accounts receivable with customers	392,300,000		392,300,000		558,700,000
Contract costs for obtaining and fulfilling contracts	5,600,000		5,600,000		$ 6,500,000
Amortization of contract costs	$ 400,000	$ 400,000	$ 1,100,000	$ 1,000,000.0