Statement of Comprehensive Income Statement (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]
Net Income	$ 45,583	$ 30,557	$ 112,143	$ 87,459
Foreign currency translation adjustment	(891)	305	(1,208)	563
Amortization of net actuarial loss included in net periodic benefit expense or income, net of deferred tax of $925, $1,892, $2,475 and $5,672, respectively	1,447	2,956	3,872	8,871
Amortization of prior service cost or credit included in net periodic benefit expense or income, net of deferred tax of $120, $61, $362 and $184, respectively	(188)	95	(567)	284
Other Comprehensive Income, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	1,259	3,051	3,305	9,155
Total Other Comprehensive Income	368	3,356	2,097	9,718
Comprehensive Income	$ 45,951	$ 33,913	$ 114,240	$ 97,177