Consolidated Statement of Changes in Retained Earnings and Accumulated Other Comprehensive Loss (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Beginning Balance	$ 470,704
Net income	88,049	91,761	70,045
Pension and post-retirement plan adjustments, net of tax ($28,636, $11,364, and $30,849)	54,951	(28,018)	(44,218)
Ending Balance	572,347	470,704
Components of accumulated other comprehensive loss
Cumulative translation adjustments	(1,189)	4,959	829
Pension and post-retirement plan adjustments	(77,080)	(132,031)	(104,013)
Accumulated other comprehensive loss	(78,269)	(127,072)	(103,184)
Retained Earnings
Beginning Balance	747,953	708,306	676,195
Net income	88,049	91,761	70,045
Foreign currency translation adjustments	0	0	0
Pension and post-retirement plan adjustments, net of tax ($28,636, $11,364, and $30,849)	0	0	0
(Income) loss attributable to noncontrolling interests	198	(1,124)	(193)
Common dividends	(43,952)	(50,948)	(37,699)
Preferred dividends	(42)	(42)	(42)
Ending Balance	792,206	747,953	708,306
Accumulated Other Comprehensive (Loss) Income
Beginning Balance	(127,072)	(103,184)	(44,316)
Net income	0	0	0
Foreign currency translation adjustments	(7,281)	3,846	(15,980)
Pension and post-retirement plan adjustments, net of tax ($28,636, $11,364, and $30,849)	54,951	(28,018)	(44,218)
(Income) loss attributable to noncontrolling interests	1,133	284	1,330
Common dividends	0	0	0
Preferred dividends	0	0	0
Ending Balance	$ (78,269)	$ (127,072)	$ (103,184)