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	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
ASSETS
Cash and cash equivalents	$ 217.0	$ 382.0	$ 109.9		$ 141.6
Accounts receivable, net	565.1	527.8
Intercompany notes receivable	0.0	0.0
Short-term contract assets	48.7	51.2	38.6	$ 36.5
Inventories, net	1,254.4	1,211.1
Prepaid expenses and other current assets	92.7	74.6
Total current assets	2,177.9	2,246.7
Property, plant and equipment, net	2,470.7	2,475.0
Goodwill	536.8	534.7
Intercompany notes receivable	0.0	0.0
Long-term contract assets	0.1	0.1	16.1	16.9
Investment in subsidiaries	0.0	0.0
Other assets	305.6	245.4
Total assets	5,491.0	5,501.8
LIABILITIES AND EQUITY
Accounts payable	455.3	498.8
Accrued liabilities	220.4	260.1
Intercompany notes payable	0.0	0.0
Short-term contract liabilities	77.9	71.4	66.2	69.7
Short-term debt and current portion of long-term debt	6.4	6.6
Total current liabilities	760.0	836.9
Long-term debt	1,536.2	1,535.5
Intercompany notes payable	0.0	0.0
Accrued postretirement benefits	309.5	318.4
Pension liabilities	701.1	730.0
Deferred income taxes	14.5	12.9
Long-term contract liabilities	7.3	7.3	19.7	$ 22.2
Other long-term liabilities	123.1	76.5
Total liabilities	3,444.4	3,510.2
Total stockholders’ equity	2,046.6	1,991.6	$ 1,963.3		$ 1,844.5
Total Liabilities and Equity	5,491.0	5,501.8
Reportable Legal Entities \| Parent Company
ASSETS
Cash and cash equivalents	0.3	0.1
Accounts receivable, net	0.0	0.0
Intercompany notes receivable	0.0	0.0
Short-term contract assets	0.0	0.0
Inventories, net	0.0	0.0
Prepaid expenses and other current assets	7.0	12.9
Total current assets	7.3	13.0
Property, plant and equipment, net	2.7	1.7
Goodwill	0.0	0.0
Intercompany notes receivable	0.0	0.0
Investment in subsidiaries	6,183.1	6,096.4
Other assets	43.0	35.6
Total assets	6,236.1	6,146.7
LIABILITIES AND EQUITY
Accounts payable	5.1	3.3
Accrued liabilities	27.3	59.1
Intercompany notes payable	2,186.7	2,102.8
Short-term contract liabilities	0.0	0.0
Short-term debt and current portion of long-term debt	0.4	0.2
Total current liabilities	2,219.5	2,165.4
Long-term debt	1,280.1	1,278.8
Intercompany notes payable	0.0	0.0
Accrued postretirement benefits	0.0	0.0
Pension liabilities	653.4	681.6
Deferred income taxes	14.5	12.9
Other long-term liabilities	22.0	16.4
Total liabilities	4,189.5	4,155.1
Total stockholders’ equity	2,046.6	1,991.6
Total Liabilities and Equity	6,236.1	6,146.7
Reportable Legal Entities \| Subsidiary
ASSETS
Cash and cash equivalents	12.5	10.8
Accounts receivable, net	157.0	126.3
Intercompany notes receivable	0.0	0.0
Short-term contract assets	0.0	0.0
Inventories, net	250.4	216.1
Prepaid expenses and other current assets	47.7	29.3
Total current assets	467.6	382.5
Property, plant and equipment, net	1,538.0	1,548.4
Goodwill	0.0	0.0
Intercompany notes receivable	0.0	0.0
Investment in subsidiaries	37.7	37.7
Other assets	54.1	30.7
Total assets	2,097.4	1,999.3
LIABILITIES AND EQUITY
Accounts payable	174.7	177.5
Accrued liabilities	74.8	71.7
Intercompany notes payable	1,971.9	1,866.0
Short-term contract liabilities	50.3	33.0
Short-term debt and current portion of long-term debt	0.1	0.7
Total current liabilities	2,271.8	2,148.9
Long-term debt	149.7	151.8
Intercompany notes payable	200.0	200.0
Accrued postretirement benefits	255.4	259.2
Pension liabilities	3.8	4.0
Deferred income taxes	0.0	0.0
Other long-term liabilities	36.8	17.6
Total liabilities	2,917.5	2,781.5
Total stockholders’ equity	(820.1)	(782.2)
Total Liabilities and Equity	2,097.4	1,999.3
Reportable Legal Entities \| NonGuarantor Subsidiaries
ASSETS
Cash and cash equivalents	204.2	371.1
Accounts receivable, net	408.1	401.5
Intercompany notes receivable	4,158.6	3,968.8
Short-term contract assets	48.7	51.2
Inventories, net	1,004.0	995.0
Prepaid expenses and other current assets	38.0	32.4
Total current assets	5,861.6	5,820.0
Property, plant and equipment, net	930.0	924.9
Goodwill	536.8	534.7
Intercompany notes receivable	200.0	200.0
Investment in subsidiaries	0.0	0.0
Other assets	208.5	179.1
Total assets	7,736.9	7,658.7
LIABILITIES AND EQUITY
Accounts payable	275.5	318.0
Accrued liabilities	118.3	129.3
Intercompany notes payable	0.0	0.0
Short-term contract liabilities	27.6	38.4
Short-term debt and current portion of long-term debt	5.9	5.7
Total current liabilities	427.3	491.4
Long-term debt	106.4	104.9
Intercompany notes payable	0.0	0.0
Accrued postretirement benefits	54.1	59.2
Pension liabilities	43.9	44.4
Deferred income taxes	0.0	0.0
Other long-term liabilities	64.3	42.5
Total liabilities	696.0	742.4
Total stockholders’ equity	7,040.9	6,916.3
Total Liabilities and Equity	7,736.9	7,658.7
Eliminations
ASSETS
Cash and cash equivalents	0.0	0.0
Accounts receivable, net	0.0	0.0
Intercompany notes receivable	(4,158.6)	(3,968.8)
Short-term contract assets	0.0	0.0
Inventories, net	0.0	0.0
Prepaid expenses and other current assets	0.0	0.0
Total current assets	(4,158.6)	(3,968.8)
Property, plant and equipment, net	0.0	0.0
Goodwill	0.0	0.0
Intercompany notes receivable	(200.0)	(200.0)
Investment in subsidiaries	(6,220.8)	(6,134.1)
Other assets	0.0	0.0
Total assets	(10,579.4)	(10,302.9)
LIABILITIES AND EQUITY
Accounts payable	0.0	0.0
Accrued liabilities	0.0	0.0
Intercompany notes payable	(4,158.6)	(3,968.8)
Short-term contract liabilities	0.0	0.0
Short-term debt and current portion of long-term debt	0.0	0.0
Total current liabilities	(4,158.6)	(3,968.8)
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
Other long-term liabilities	0.0	0.0
Total liabilities	(4,358.6)	(4,168.8)
Total stockholders’ equity	(6,220.8)	(6,134.1)
Total Liabilities and Equity	$ (10,579.4)	$ (10,302.9)