Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Schedule Of Basic Weighted Average Shares Reconciles To Diluted Weighted Average Shares

Basic weighted average shares outstanding reconciles to diluted weighted average shares outstanding as follows:

	2017	2016	2015
	(In thousands)
Basic weighted average common shares outstanding	76,232	75,803	77,126
Dilutive effect of stock options, restricted stock and performance share units	1,101	955	846
Diluted weighted average common shares outstanding	77,333	76,758	77,972

Property And Equipment At Cost, Depreciation And Amortization Estimated Useful Lives

Property and equipment are stated at cost, with depreciation and amortization provided using the straight-line method over the following estimated useful lives:

Land improvements	8 to 12 years
Buildings and improvements	8 to 30 years
Machinery, equipment and other	3 to 12 years
Office and transportation equipment	3 to 10 years

Schedule of Identifiable Intangible Assets, Useful Lives

Certain identifiable intangible assets are amortized over their estimated useful lives using the straight-line method. The estimated useful lives used in the computation of amortization of identifiable intangible assets are as follows:

Patents	5 to 17 years
Trade names	10 to 20 years
Customer relationships	6 to 20 years
Unpatented technology and other	6 to 20 years