Consolidated Statements of Income (Parenthetical) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Consolidated Condensed Statements Of Income [Abstract]
Pension and post-retirement plans expense reclassified from accumulated other comprehensive income	$ 1,600,000	$ 1,100,000	$ 3,400,000	$ 1,700,000
Income tax benefit reclassified from accumulated other comprehensive income	$ 600,000	$ 400,000	$ 1,300,000	$ 700,000

Amount before tax of reclassification adjustment from accumulated other comprehensive (income) loss related to net period benefit cost (credit) for pension and other postretirement defined benefit plans.

No definition available.

Name:	us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration