Accumulated Other Comprehensive Income (Loss) (Components of Accumulated Other Comprehensive Income or Loss) (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance $ (65,094) $ (11,450)    
Other comprehensive income before reclassifications (27,856) (507)    
Amounts reclassified from accumulated other comprehensive income 362 349    
Net current-period other comprehensive income (27,494) (158)    
Ending balance (92,588) (11,608)    
AOCI, Pension and other postretirement benefit plans, tax 11,807 2,825 11,952 2,900
AOCI, Cumulative changes in net gain (loss) from cash flow hedges, tax 50 96 50 110
Foreign currency translation adjustments [Member]        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance (14,193) 22,756    
Other comprehensive income before reclassifications (27,980) (327)    
Amounts reclassified from accumulated other comprehensive income 0 0    
Net current-period other comprehensive income (27,980) (327)    
Ending balance (42,173) 22,429    
Funded status of pension plans and other postretirement benefits [Member]        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance (50,808) [1] (33,997) [2]    
Other comprehensive income before reclassifications 0 [1] 0 [2]    
Amounts reclassified from accumulated other comprehensive income 268 [1] 139 [2]    
Net current-period other comprehensive income 268 [1] 139 [2]    
Ending balance (50,540) [1] (33,858) [2]    
Unrealized gain (loss) on derivative instruments [Member]        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance (93) [3] (209) [4]    
Other comprehensive income before reclassifications 124 [3] (180) [4]    
Amounts reclassified from accumulated other comprehensive income 94 [3] 210 [4]    
Net current-period other comprehensive income 218 [3] 30 [4]    
Ending balance $ 125 [3] $ (179) [4]    
[1] Net of taxes of $11,807 and $11,952 for the periods ended March 31, 2015 and December 31, 2014, respectively.
[2] Net of taxes of $2,825 and $2,900 for the periods ended March 31, 2014 and December 31, 2013, respectively.
[3] Net of taxes of $50 and $50 for the periods ended March 31, 2015 and December 31, 2014, respectively.
[4] Net of taxes of $96 and $110 for the periods ended March 31, 2014 and December 31, 2013, respectively.