Shareholders' Equity (Schedule of Activity in Shareholders' Equity) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Balance			$ 502,553
Net income	$ 10,101	$ (2,120)	23,417	$ 10,119
Compensation and benefits paid or payable in shares			1,152
Options exercised			495
Shares issued to Directors'			380
Dividends declared			(10,911)
Cumulative translation adjustments			2,392
Pension and postretirement liability adjustments			361
Derivative valuation adjustment			(4,245)
Balance	515,594		515,594
Common Stock [Member]
Balance			40
Net income
Compensation and benefits paid or payable in shares
Options exercised
Shares issued to Directors'
Dividends declared
Cumulative translation adjustments
Pension and postretirement liability adjustments
Derivative valuation adjustment
Balance	40		40
Additional Paid-in Capital [Member]
Balance			423,108
Net income
Compensation and benefits paid or payable in shares			1,152
Options exercised			495
Shares issued to Directors'			166
Dividends declared
Cumulative translation adjustments
Pension and postretirement liability adjustments
Derivative valuation adjustment
Balance	424,921		424,921
Retained Earnings [Member]
Balance			491,950
Net income			23,868
Compensation and benefits paid or payable in shares
Options exercised
Shares issued to Directors'
Dividends declared			(10,911)
Cumulative translation adjustments
Pension and postretirement liability adjustments
Derivative valuation adjustment
Balance	504,907		504,907
Accumulated Other Comprehensive Income (Loss) [Member]
Balance			(158,844)
Net income
Compensation and benefits paid or payable in shares
Options exercised
Shares issued to Directors'
Dividends declared
Cumulative translation adjustments			2,393
Pension and postretirement liability adjustments			361
Derivative valuation adjustment			(4,245)
Balance	(160,335)		(160,335)
Treasury Stock [Member]
Balance			(257,391)
Net income
Compensation and benefits paid or payable in shares
Options exercised
Shares issued to Directors'			214
Dividends declared
Cumulative translation adjustments
Pension and postretirement liability adjustments
Derivative valuation adjustment
Balance	(257,177)		(257,177)
Noncontrolling Interest [Member]
Balance			3,690
Net income			(451)
Compensation and benefits paid or payable in shares
Options exercised
Shares issued to Directors'
Dividends declared
Cumulative translation adjustments			(1)
Pension and postretirement liability adjustments
Derivative valuation adjustment
Balance	$ 3,238		$ 3,238