Changes in Shareholders' Equity (Schedule of Activity in Shareholders' Equity) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Balance			$ 511,290,000
Net income	$ 1,233,000	$ 10,101,000	12,207,000	$ 23,417,000
Compensation and benefits paid or payable in shares			1,670,000
Options exercised			175,000
Dividends declared			(10,936,000)
Cumulative translation adjustments			28,466,000
Pension and postretirement liability adjustments			(747,000)
Derivative valuation adjustment			(34,000)
Balance	542,091,000		542,091,000
Common Stock [Member]
Balance			40,000
Net income
Compensation and benefits paid or payable in shares
Options exercised
Dividends declared
Cumulative translation adjustments
Pension and postretirement liability adjustments
Derivative valuation adjustment
Balance	40,000		40,000
Additional Paid-in Capital [Member]
Balance			425,953,000
Net income
Compensation and benefits paid or payable in shares			1,410,000
Options exercised			175,000
Dividends declared
Cumulative translation adjustments
Pension and postretirement liability adjustments
Derivative valuation adjustment
Balance	427,538,000		427,538,000
Retained Earnings [Member]
Balance			522,855,000
Net income			11,956,000
Compensation and benefits paid or payable in shares
Options exercised
Dividends declared			(10,936,000)
Cumulative translation adjustments
Pension and postretirement liability adjustments
Derivative valuation adjustment
Balance	523,875,000		523,875,000
Total Other Comprehensive Income [Member]
Balance			(184,189,000)
Net income
Compensation and benefits paid or payable in shares
Options exercised
Dividends declared
Cumulative translation adjustments			28,453,000
Pension and postretirement liability adjustments			(747,000)
Derivative valuation adjustment			(34,000)
Balance	(156,517,000)		(156,517,000)
Treasury Stock [Member]
Balance			(257,136,000)
Net income
Compensation and benefits paid or payable in shares			260,000
Options exercised
Dividends declared
Cumulative translation adjustments
Pension and postretirement liability adjustments
Derivative valuation adjustment
Balance	(256,876,000)		(256,876,000)
Noncontrolling Interest [Member]
Balance			3,767,000
Net income			251,000
Compensation and benefits paid or payable in shares
Options exercised
Dividends declared
Cumulative translation adjustments			13,000
Pension and postretirement liability adjustments
Derivative valuation adjustment
Balance	$ 4,031,000		$ 4,031,000