Pension and Other Postretirement Plans (Multi-Employer Plans) - Additional Information (Detail) - Multiemployer Plans, Pension - IAM National Pension Plan $ in Millions	12 Months Ended
Dec. 31, 2015 USD ($)
Multiemployer Plans [Line Items]
Multi-employer plan contributions	$ 395
Minimum
Multiemployer Plans [Line Items]
Percent of company's contribution to plan	5.00%

Amount of contributions made to the multiemployer plan by all employers who participate in the plan. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 7
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450678-114947

Name:	us-gaap_MultiemployerPlansPlanContributions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration