Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Consolidated Statements of Comprehensive Income
Reclassification of pension liability adjustments to earnings, tax (benefit) expense	$ 47	$ 26	$ 93	$ 47

Amount of tax (expense) benefit of reclassification adjustment from accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.

No definition available.

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