Consolidated Statement of Changes in Retained Earnings and Accumulated Other Comprehensive Loss Statement (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 572,347
Net income	13,917	19,395
Pension and post-retirement plan adjustments, net of tax of $805 and $1,278	1,418	2,107
Ending balance	580,888
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	792,206	747,953
Net income	13,917	19,395
Foreign currency translation adjustments	0	0
Pension and post-retirement plan adjustments, net of tax of $805 and $1,278	0	0
(Income) loss attributable to noncontrolling interests	109	(109)
Common dividends	(11,171)	(10,362)
Preferred dividends	(10)	(10)
Ending balance	795,051	756,867
Accumulated Other Comprehensive (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(78,269)	(127,072)
Net income	0	0
Foreign currency translation adjustments	(958)	(5,588)
Pension and post-retirement plan adjustments, net of tax of $805 and $1,278	1,418	2,107
(Income) loss attributable to noncontrolling interests	142	548
Common dividends	0	0
Preferred dividends	0	0
Ending balance	$ (77,667)	$ (130,005)