Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Name:	us-gaap_AccountsPayableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130549-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Financial Information for Subsidiary and Guarantor Parent (B.S.) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 153.5		$ 141.6	$ 124.9	$ 229.6
Accounts receivable, net	588.3		545.3
Intercompany notes receivable	0.0		0.0
Short-term contract assets	51.6	$ 36.5	0.0
Inventories, net	1,239.8		1,176.1
Prepaid expenses and other current assets	89.2		52.7
Total current assets	2,122.4		1,915.7
Property, plant and equipment, net	2,472.6		2,495.7
Goodwill	536.4		531.4
Intercompany notes receivable	0.0		0.0
Long-term contract assets	0.1	16.9
Investment in subsidiaries	0.0		0.0
Other assets	257.6		242.6
Total assets	5,389.0		5,185.4
LIABILITIES AND EQUITY
Accounts payable	416.1		420.1
Accrued liabilities	228.7		282.4
Intercompany notes payable	0.0		0.0
Short-term contract liabilities	69.2	69.7	0.0
Short-term debt and current portion of long-term debt	16.6		10.1
Total current liabilities	730.6		712.6
Long-term debt	1,535.3		1,530.6
Intercompany notes payable	0.0		0.0
Accrued postretirement benefits	301.1		317.8
Pension liabilities	652.7		697.0
Deferred income taxes	12.1		9.7
Long-term contract liabilities	7.3	$ 22.2	0.0
Other long-term liabilities	66.7		73.2
Total liabilities	3,305.8		3,340.9
Total stockholders’ equity	2,083.2		1,844.5	$ 1,447.5	$ 1,444.8
Total Liabilities and Equity	5,389.0		5,185.4
Reportable Legal Entities \| Parent Company
ASSETS
Cash and cash equivalents	1.1		2.1
Accounts receivable, net	0.0		0.2
Intercompany notes receivable	0.0		0.0
Short-term contract assets	0.0
Inventories, net	0.0		0.0
Prepaid expenses and other current assets	14.7		6.6
Total current assets	15.8		8.9
Property, plant and equipment, net	0.7		0.9
Goodwill	0.0		0.0
Intercompany notes receivable	0.0		0.0
Investment in subsidiaries	6,131.9		5,645.6
Other assets	34.1		25.4
Total assets	6,182.5		5,680.8
LIABILITIES AND EQUITY
Accounts payable	4.6		3.0
Accrued liabilities	37.3		54.1
Intercompany notes payable	2,144.5		1,836.5
Short-term contract liabilities	0.0
Short-term debt and current portion of long-term debt	0.2		0.3
Total current liabilities	2,186.6		1,893.9
Long-term debt	1,277.5		1,275.7
Intercompany notes payable	0.0		0.0
Accrued postretirement benefits	0.0		0.0
Pension liabilities	602.0		644.3
Deferred income taxes	12.1		9.7
Long-term contract liabilities	0.0
Other long-term liabilities	21.1		12.7
Total liabilities	4,099.3		3,836.3
Total stockholders’ equity	2,083.2		1,844.5
Total Liabilities and Equity	6,182.5		5,680.8
Reportable Legal Entities \| Subsidiary
ASSETS
Cash and cash equivalents	6.8		13.5
Accounts receivable, net	156.4		141.6
Intercompany notes receivable	0.0		0.0
Short-term contract assets	0.0
Inventories, net	238.6		207.9
Prepaid expenses and other current assets	38.4		4.5
Total current assets	440.2		367.5
Property, plant and equipment, net	1,551.6		1,581.6
Goodwill	0.0		0.0
Intercompany notes receivable	0.0		0.0
Investment in subsidiaries	37.7		37.7
Other assets	40.5		18.0
Total assets	2,070.0		2,004.8
LIABILITIES AND EQUITY
Accounts payable	153.4		180.3
Accrued liabilities	68.8		88.5
Intercompany notes payable	1,769.0		1,669.1
Short-term contract liabilities	30.7
Short-term debt and current portion of long-term debt	0.8		0.6
Total current liabilities	2,022.7		1,938.5
Long-term debt	152.0		150.7
Intercompany notes payable	200.0		200.0
Accrued postretirement benefits	243.8		250.2
Pension liabilities	3.9		4.4
Deferred income taxes	0.0		0.0
Long-term contract liabilities	0.0
Other long-term liabilities	17.5		17.2
Total liabilities	2,639.9		2,561.0
Total stockholders’ equity	(569.9)		(556.2)
Total Liabilities and Equity	2,070.0		2,004.8
Reportable Legal Entities \| NonGuarantor Subsidiaries
ASSETS
Cash and cash equivalents	145.6		126.0
Accounts receivable, net	431.9		403.5
Intercompany notes receivable	3,913.5		3,505.6
Short-term contract assets	51.6
Inventories, net	1,001.2		968.2
Prepaid expenses and other current assets	36.1		41.6
Total current assets	5,579.9		5,044.9
Property, plant and equipment, net	920.3		913.2
Goodwill	536.4		531.4
Intercompany notes receivable	200.0		200.0
Investment in subsidiaries	0.0		0.0
Other assets	183.0		199.2
Total assets	7,419.6		6,888.7
LIABILITIES AND EQUITY
Accounts payable	258.1		236.8
Accrued liabilities	122.6		139.8
Intercompany notes payable	0.0		0.0
Short-term contract liabilities	38.5
Short-term debt and current portion of long-term debt	15.6		9.2
Total current liabilities	434.8		385.8
Long-term debt	105.8		104.2
Intercompany notes payable	0.0		0.0
Accrued postretirement benefits	57.3		67.6
Pension liabilities	46.8		48.3
Deferred income taxes	0.0		0.0
Long-term contract liabilities	7.3
Other long-term liabilities	28.1		43.3
Total liabilities	680.1		649.2
Total stockholders’ equity	6,739.5		6,239.5
Total Liabilities and Equity	7,419.6		6,888.7
Eliminations
ASSETS
Cash and cash equivalents	0.0		0.0
Accounts receivable, net	0.0		0.0
Intercompany notes receivable	(3,913.5)		(3,505.6)
Short-term contract assets	0.0
Inventories, net	0.0		0.0
Prepaid expenses and other current assets	0.0		0.0
Total current assets	(3,913.5)		(3,505.6)
Property, plant and equipment, net	0.0		0.0
Goodwill	0.0		0.0
Intercompany notes receivable	(200.0)		(200.0)
Investment in subsidiaries	(6,169.6)		(5,683.3)
Other assets	0.0		0.0
Total assets	(10,283.1)		(9,388.9)
LIABILITIES AND EQUITY
Accounts payable	0.0		0.0
Accrued liabilities	0.0		0.0
Intercompany notes payable	(3,913.5)		(3,505.6)
Short-term contract liabilities	0.0
Short-term debt and current portion of long-term debt	0.0		0.0
Total current liabilities	(3,913.5)		(3,505.6)
Long-term debt	0.0		0.0
Intercompany notes payable	(200.0)		(200.0)
Accrued postretirement benefits	0.0		0.0
Pension liabilities	0.0		0.0
Deferred income taxes	0.0		0.0
Long-term contract liabilities	0.0
Other long-term liabilities	0.0		0.0
Total liabilities	(4,113.5)		(3,705.6)
Total stockholders’ equity	(6,169.6)		(5,683.3)
Total Liabilities and Equity	$ (10,283.1)		$ (9,388.9)