Accumulated Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncome [Line Items]
Total employee benefit amounts reclassified from accumulated other comprehensive loss, net of tax	$ 872
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Defined Benefit Plans Adjustment
ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncome [Line Items]
Amortization of actuarial loss	1,463	[1]
Total employee benefit amounts reclassified from accumulated other comprehensive loss	1,463
Tax on employee benefit amounts reclassified from accumulated other comprehensive loss	(591)
Total employee benefit amounts reclassified from accumulated other comprehensive loss, net of tax	$ 872

[1] These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. See note (9) "Employee Benefit Plans" for details.